sunshinejnjn
commented
6 years ago Hi,
With pyshp, you do “import shapefile”. That was completely the right way to do it because shapefile is the module file name which will be installed as a standalone file (not a directory) in the libs directory. However, I've found that there is a new version (2.0.0-dev) of pyshp which is what you need to run your code (with the new API of the new version). But you can't install it by pip. Download the file from here https://github.com/GeospatialPython/pyshp/blob/master/shapefile.py And put the file in the same directory of your program and do "import shapefile", your code will probably run.
-- Best, Yi
On 30 May 2018 at 14:23, Samuel Campos notifications@github.com wrote:
Hi I'm working with Anaconda and Python 2.7, and I installed pyshp using conda-forge. To test, I imported the library like this:
import pyshp
However, the following error appeared:
ImportError: No module named pyshp
But when I do this:
import shapefile
no errors appear. Just to test, I uninstalled the library and reinstalled using pip, but the same thing happens. I really need to import pyshp, because with shapefile my code does not run (I also do not know the reason).
Thanks for the help :)
— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/GeospatialPython/pyshp/issues/142, or mute the thread https://github.com/notifications/unsubscribe-auth/AJ0TAc_4XzpPRuO3cgiduUlcyjVX-aicks5t3p1qgaJpZM4UTRN5 .
-- Regards, JnJn
"""
shapefile.py
Provides read and write support for ESRI Shapefiles.
author: jlawhead
version = "2.0.0-dev"
from struct import pack, unpack, calcsize, error, Struct import os import sys import time import array import tempfile import itertools import io from datetime import date
Constants for shape types
NULL = 0 POINT = 1 POLYLINE = 3 POLYGON = 5 MULTIPOINT = 8 POINTZ = 11 POLYLINEZ = 13 POLYGONZ = 15 MULTIPOINTZ = 18 POINTM = 21 POLYLINEM = 23 POLYGONM = 25 MULTIPOINTM = 28 MULTIPATCH = 31
Python 2-3 handling
PYTHON3 = sys.version_info[0] == 3
if PYTHON3: xrange = range izip = zip else: from itertools import izip
Helpers
MISSING = [None,'']
if PYTHON3: def b(v, encoding='utf-8', encodingErrors='strict'): if isinstance(v, str):
For python 3 encode str to bytes.
return v.encode(encoding, encodingErrors)
elif isinstance(v, bytes):
# Already bytes.
return v
else:
# Error.
raise Exception('Unknown input type')
def u(v, encoding='utf-8', encodingErrors='strict'):
if isinstance(v, bytes):
# For python 3 decode bytes to str.
return v.decode(encoding, encodingErrors)
elif isinstance(v, str):
# Already str.
return v
else:
# Error.
raise Exception('Unknown input type')
def is_string(v):
return isinstance(v, str)else: def b(v, encoding='utf-8', encodingErrors='strict'): if isinstance(v, unicode):
For python 2 encode unicode to bytes.
return v.encode(encoding, encodingErrors)
elif isinstance(v, bytes):
# Already bytes.
return v
else:
# Error.
raise Exception('Unknown input type')
def u(v, encoding='utf-8', encodingErrors='strict'):
if isinstance(v, bytes):
# For python 2 decode bytes to unicode.
return v.decode(encoding, encodingErrors)
elif isinstance(v, unicode):
# Already unicode.
return v
else:
# Error.
raise Exception('Unknown input type')
def is_string(v):
return isinstance(v, basestring)Begin
class _Array(array.array): """Converts python tuples to lits of the appropritate type. Used to unpack different shapefile header parts.""" def repr(self): return str(self.tolist())
def signed_area(coords): """Return the signed area enclosed by a ring using the linear time algorithm. A value >= 0 indicates a counter-clockwise oriented ring. """ xs, ys = map(list, zip(coords)) xs.append(xs[1]) ys.append(ys[1]) return sum(xs[i](ys[i+1]-ys[i-1]) for i in range(1, len(coords)))/2.0
def geojson_to_shape(geoj):
create empty shape
shape = Shape()
# set shapeType
geojType = geoj["type"] if geoj else "Null"
if geojType == "Null":
shapeType = NULL
elif geojType == "Point":
shapeType = POINT
elif geojType == "LineString":
shapeType = POLYLINE
elif geojType == "Polygon":
shapeType = POLYGON
elif geojType == "MultiPoint":
shapeType = MULTIPOINT
elif geojType == "MultiLineString":
shapeType = POLYLINE
elif geojType == "MultiPolygon":
shapeType = POLYGON
else:
raise Exception("Cannot create Shape from GeoJSON type '%s'" % geojType)
shape.shapeType = shapeType
# set points and parts
if geojType == "Point":
shape.points = [ geoj["coordinates"] ]
shape.parts = [0]
elif geojType in ("MultiPoint","LineString"):
shape.points = geoj["coordinates"]
shape.parts = [0]
elif geojType in ("Polygon"):
points = []
parts = []
index = 0
for ext_or_hole in geoj["coordinates"]:
points.extend(ext_or_hole)
parts.append(index)
index += len(ext_or_hole)
shape.points = points
shape.parts = parts
elif geojType in ("MultiLineString"):
points = []
parts = []
index = 0
for linestring in geoj["coordinates"]:
points.extend(linestring)
parts.append(index)
index += len(linestring)
shape.points = points
shape.parts = parts
elif geojType in ("MultiPolygon"):
points = []
parts = []
index = 0
for polygon in geoj["coordinates"]:
for ext_or_hole in polygon:
points.extend(ext_or_hole)
parts.append(index)
index += len(ext_or_hole)
shape.points = points
shape.parts = parts
return shapeclass Shape: def init(self, shapeType=NULL, points=None, parts=None, partTypes=None): """Stores the geometry of the different shape types specified in the Shapefile spec. Shape types are usually point, polyline, or polygons. Every shape type except the "Null" type contains points at some level for example verticies in a polygon. If a shape type has multiple shapes containing points within a single geometry record then those shapes are called parts. Parts are designated by their starting index in geometry record's list of shapes. For MultiPatch geometry, partTypes designates the patch type of each of the parts. """ self.shapeType = shapeType self.points = points or [] self.parts = parts or [] if partTypes: self.partTypes = partTypes
@property
def __geo_interface__(self):
if self.shapeType in [POINT, POINTM, POINTZ]:
return {
'type': 'Point',
'coordinates': tuple(self.points[0])
}
elif self.shapeType in [MULTIPOINT, MULTIPOINTM, MULTIPOINTZ]:
return {
'type': 'MultiPoint',
'coordinates': tuple([tuple(p) for p in self.points])
}
elif self.shapeType in [POLYLINE, POLYLINEM, POLYLINEZ]:
if len(self.parts) == 1:
return {
'type': 'LineString',
'coordinates': tuple([tuple(p) for p in self.points])
}
else:
ps = None
coordinates = []
for part in self.parts:
if ps == None:
ps = part
continue
else:
coordinates.append(tuple([tuple(p) for p in self.points[ps:part]]))
ps = part
else:
coordinates.append(tuple([tuple(p) for p in self.points[part:]]))
return {
'type': 'MultiLineString',
'coordinates': tuple(coordinates)
}
elif self.shapeType in [POLYGON, POLYGONM, POLYGONZ]:
if len(self.parts) == 1:
return {
'type': 'Polygon',
'coordinates': (tuple([tuple(p) for p in self.points]),)
}
else:
ps = None
coordinates = []
for part in self.parts:
if ps == None:
ps = part
continue
else:
coordinates.append(tuple([tuple(p) for p in self.points[ps:part]]))
ps = part
else:
coordinates.append(tuple([tuple(p) for p in self.points[part:]]))
polys = []
poly = [coordinates[0]]
for coord in coordinates[1:]:
if signed_area(coord) < 0:
polys.append(poly)
poly = [coord]
else:
poly.append(coord)
polys.append(poly)
if len(polys) == 1:
return {
'type': 'Polygon',
'coordinates': tuple(polys[0])
}
elif len(polys) > 1:
return {
'type': 'MultiPolygon',
'coordinates': polys
}class ShapeRecord: """A ShapeRecord object containing a shape along with its attributes.""" def init(self, shape=None, record=None): self.shape = shape self.record = record
class ShapefileException(Exception): """An exception to handle shapefile specific problems.""" pass
class Reader: """Reads the three files of a shapefile as a unit or separately. If one of the three files (.shp, .shx, .dbf) is missing no exception is thrown until you try to call a method that depends on that particular file. The .shx index file is used if available for efficiency but is not required to read the geometry from the .shp file. The "shapefile" argument in the constructor is the name of the file you want to open.
You can instantiate a Reader without specifying a shapefile
and then specify one later with the load() method.
Only the shapefile headers are read upon loading. Content
within each file is only accessed when required and as
efficiently as possible. Shapefiles are usually not large
but they can be.
"""
def __init__(self, *args, **kwargs):
self.shp = None
self.shx = None
self.dbf = None
self.shapeName = "Not specified"
self._offsets = []
self.shpLength = None
self.numRecords = None
self.fields = []
self.__dbfHdrLength = 0
self.encoding = kwargs.pop('encoding', 'utf-8')
self.encodingErrors = kwargs.pop('encodingErrors', 'strict')
# See if a shapefile name was passed as an argument
if len(args) > 0:
if is_string(args[0]):
self.load(args[0])
return
if "shp" in kwargs.keys():
if hasattr(kwargs["shp"], "read"):
self.shp = kwargs["shp"]
# Copy if required
try:
self.shp.seek(0)
except (NameError, io.UnsupportedOperation):
self.shp = io.BytesIO(self.shp.read())
if "shx" in kwargs.keys():
if hasattr(kwargs["shx"], "read"):
self.shx = kwargs["shx"]
# Copy if required
try:
self.shx.seek(0)
except (NameError, io.UnsupportedOperation):
self.shx = io.BytesIO(self.shx.read())
if "dbf" in kwargs.keys():
if hasattr(kwargs["dbf"], "read"):
self.dbf = kwargs["dbf"]
# Copy if required
try:
self.dbf.seek(0)
except (NameError, io.UnsupportedOperation):
self.dbf = io.BytesIO(self.dbf.read())
if self.shp or self.dbf:
self.load()
else:
raise ShapefileException("Shapefile Reader requires a shapefile or file-like object.")
def __len__(self):
"""Returns the number of shapes/records in the shapefile."""
return self.numRecords
def load(self, shapefile=None):
"""Opens a shapefile from a filename or file-like
object. Normally this method would be called by the
constructor with the file name as an argument."""
if shapefile:
(shapeName, ext) = os.path.splitext(shapefile)
self.shapeName = shapeName
try:
self.shp = open("%s.shp" % shapeName, "rb")
except IOError:
pass
try:
self.shx = open("%s.shx" % shapeName, "rb")
except IOError:
pass
try:
self.dbf = open("%s.dbf" % shapeName, "rb")
except IOError:
pass
if not (self.shp and self.dbf):
raise ShapefileException("Unable to open %s.dbf or %s.shp." % (shapeName, shapeName) )
if self.shp:
self.__shpHeader()
if self.dbf:
self.__dbfHeader()
def __del__(self):
self.close()
def close(self):
try:
if hasattr(self.shp, 'close'):
self.shp.close()
if hasattr(self.shx, 'close'):
self.shx.close()
if hasattr(self.dbf, 'close'):
self.dbf.close()
except IOError:
pass
def __getFileObj(self, f):
"""Checks to see if the requested shapefile file object is
available. If not a ShapefileException is raised."""
if not f:
raise ShapefileException("Shapefile Reader requires a shapefile or file-like object.")
if self.shp and self.shpLength is None:
self.load()
if self.dbf and len(self.fields) == 0:
self.load()
return f
def __restrictIndex(self, i):
"""Provides list-like handling of a record index with a clearer
error message if the index is out of bounds."""
if self.numRecords:
rmax = self.numRecords - 1
if abs(i) > rmax:
raise IndexError("Shape or Record index out of range.")
if i < 0: i = range(self.numRecords)[i]
return i
def __shpHeader(self):
"""Reads the header information from a .shp or .shx file."""
if not self.shp:
raise ShapefileException("Shapefile Reader requires a shapefile or file-like object. (no shp file found")
shp = self.shp
# File length (16-bit word * 2 = bytes)
shp.seek(24)
self.shpLength = unpack(">i", shp.read(4))[0] * 2
# Shape type
shp.seek(32)
self.shapeType= unpack("<i", shp.read(4))[0]
# The shapefile's bounding box (lower left, upper right)
self.bbox = _Array('d', unpack("<4d", shp.read(32)))
# Elevation
self.elevation = _Array('d', unpack("<2d", shp.read(16)))
# Measure
self.measure = _Array('d', unpack("<2d", shp.read(16)))
def __shape(self):
"""Returns the header info and geometry for a single shape."""
f = self.__getFileObj(self.shp)
record = Shape()
nParts = nPoints = zmin = zmax = mmin = mmax = None
(recNum, recLength) = unpack(">2i", f.read(8))
# Determine the start of the next record
next = f.tell() + (2 * recLength)
shapeType = unpack("<i", f.read(4))[0]
record.shapeType = shapeType
# For Null shapes create an empty points list for consistency
if shapeType == 0:
record.points = []
# All shape types capable of having a bounding box
elif shapeType in (3,5,8,13,15,18,23,25,28,31):
record.bbox = _Array('d', unpack("<4d", f.read(32)))
# Shape types with parts
if shapeType in (3,5,13,15,23,25,31):
nParts = unpack("<i", f.read(4))[0]
# Shape types with points
if shapeType in (3,5,8,13,15,18,23,25,28,31):
nPoints = unpack("<i", f.read(4))[0]
# Read parts
if nParts:
record.parts = _Array('i', unpack("<%si" % nParts, f.read(nParts * 4)))
# Read part types for Multipatch - 31
if shapeType == 31:
record.partTypes = _Array('i', unpack("<%si" % nParts, f.read(nParts * 4)))
# Read points - produces a list of [x,y] values
if nPoints:
flat = unpack("<%sd" % (2 * nPoints), f.read(16*nPoints))
record.points = list(izip(*(iter(flat),) * 2))
# Read z extremes and values
if shapeType in (13,15,18,31):
(zmin, zmax) = unpack("<2d", f.read(16))
record.z = _Array('d', unpack("<%sd" % nPoints, f.read(nPoints * 8)))
# Read m extremes and values if header m values do not equal 0.0
if shapeType in (13,15,18,23,25,28,31) and not 0.0 in self.measure:
(mmin, mmax) = unpack("<2d", f.read(16))
# Measure values less than -10e38 are nodata values according to the spec
record.m = []
for m in _Array('d', unpack("<%sd" % nPoints, f.read(nPoints * 8))):
if m > -10e38:
record.m.append(m)
else:
record.m.append(None)
# Read a single point
if shapeType in (1,11,21):
record.points = [_Array('d', unpack("<2d", f.read(16)))]
# Read a single Z value
if shapeType == 11:
record.z = unpack("<d", f.read(8))
# Read a single M value
if shapeType in (11,21):
record.m = unpack("<d", f.read(8))
# Seek to the end of this record as defined by the record header because
# the shapefile spec doesn't require the actual content to meet the header
# definition. Probably allowed for lazy feature deletion.
f.seek(next)
return record
def __shapeIndex(self, i=None):
"""Returns the offset in a .shp file for a shape based on information
in the .shx index file."""
shx = self.shx
if not shx:
return None
if not self._offsets:
# File length (16-bit word * 2 = bytes) - header length
shx.seek(24)
shxRecordLength = (unpack(">i", shx.read(4))[0] * 2) - 100
numRecords = shxRecordLength // 8
# Jump to the first record.
shx.seek(100)
shxRecords = _Array('i')
# Each offset consists of two nrs, only the first one matters
shxRecords.fromfile(shx, 2 * numRecords)
if sys.byteorder != 'big':
shxRecords.byteswap()
self._offsets = [2 * el for el in shxRecords[::2]]
if not i == None:
return self._offsets[i]
def shape(self, i=0):
"""Returns a shape object for a shape in the the geometry
record file."""
shp = self.__getFileObj(self.shp)
i = self.__restrictIndex(i)
offset = self.__shapeIndex(i)
if not offset:
# Shx index not available so iterate the full list.
for j,k in enumerate(self.iterShapes()):
if j == i:
return k
shp.seek(offset)
return self.__shape()
def shapes(self):
"""Returns all shapes in a shapefile."""
shp = self.__getFileObj(self.shp)
# Found shapefiles which report incorrect
# shp file length in the header. Can't trust
# that so we seek to the end of the file
# and figure it out.
shp.seek(0,2)
self.shpLength = shp.tell()
shp.seek(100)
shapes = []
while shp.tell() < self.shpLength:
shapes.append(self.__shape())
return shapes
def iterShapes(self):
"""Serves up shapes in a shapefile as an iterator. Useful
for handling large shapefiles."""
shp = self.__getFileObj(self.shp)
shp.seek(0,2)
self.shpLength = shp.tell()
shp.seek(100)
while shp.tell() < self.shpLength:
yield self.__shape()
def __dbfHeader(self):
"""Reads a dbf header. Xbase-related code borrows heavily from ActiveState Python Cookbook Recipe 362715 by Raymond Hettinger"""
if not self.dbf:
raise ShapefileException("Shapefile Reader requires a shapefile or file-like object. (no dbf file found)")
dbf = self.dbf
# read relevant header parts
self.numRecords, self.__dbfHdrLength, self.__recordLength = \
unpack("<xxxxLHH20x", dbf.read(32))
# read fields
numFields = (self.__dbfHdrLength - 33) // 32
for field in range(numFields):
fieldDesc = list(unpack("<11sc4xBB14x", dbf.read(32)))
name = 0
idx = 0
if b"\x00" in fieldDesc[name]:
idx = fieldDesc[name].index(b"\x00")
else:
idx = len(fieldDesc[name]) - 1
fieldDesc[name] = fieldDesc[name][:idx]
fieldDesc[name] = u(fieldDesc[name], "ascii")
fieldDesc[name] = fieldDesc[name].lstrip()
fieldDesc[1] = u(fieldDesc[1], "ascii")
self.fields.append(fieldDesc)
terminator = dbf.read(1)
if terminator != b"\r":
raise ShapefileException("Shapefile dbf header lacks expected terminator. (likely corrupt?)")
self.fields.insert(0, ('DeletionFlag', 'C', 1, 0))
fmt,fmtSize = self.__recordFmt()
self.__recStruct = Struct(fmt)
def __recordFmt(self):
"""Calculates the format and size of a .dbf record."""
if self.numRecords is None:
self.__dbfHeader()
fmt = ''.join(['%ds' % fieldinfo[2] for fieldinfo in self.fields])
fmtSize = calcsize(fmt)
# total size of fields should add up to recordlength from the header
while fmtSize < self.__recordLength:
# if not, pad byte until reaches recordlength
fmt += "x"
fmtSize += 1
return (fmt, fmtSize)
def __record(self):
"""Reads and returns a dbf record row as a list of values."""
f = self.__getFileObj(self.dbf)
recordContents = self.__recStruct.unpack(f.read(self.__recStruct.size))
if recordContents[0] != b' ':
# deleted record
return None
record = []
for (name, typ, size, deci), value in zip(self.fields, recordContents):
if name == 'DeletionFlag':
continue
elif typ in ("N","F"):
# numeric or float: number stored as a string, right justified, and padded with blanks to the width of the field.
value = value.replace(b'\0', b'').strip()
value = value.replace(b'*', b'') # QGIS NULL is all '*' chars
if value == b'':
value = None
elif deci:
try:
value = float(value)
except ValueError:
#not parseable as float, set to None
value = None
else:
# force to int
try:
# first try to force directly to int.
# forcing a large int to float and back to int
# will lose information and result in wrong nr.
value = int(value)
except ValueError:
# forcing directly to int failed, so was probably a float.
try:
value = int(float(value))
except ValueError:
#not parseable as int, set to None
value = None
elif typ == 'D':
# date: 8 bytes - date stored as a string in the format YYYYMMDD.
if value.count(b'0') == len(value): # QGIS NULL is all '0' chars
value = None
else:
try:
y, m, d = int(value[:4]), int(value[4:6]), int(value[6:8])
value = date(y, m, d)
except:
value = value.strip()
elif typ == 'L':
# logical: 1 byte - initialized to 0x20 (space) otherwise T or F.
if value == b" ":
value = None # space means missing or not yet set
else:
if value in b'YyTt1':
value = True
elif value in b'NnFf0':
value = False
else:
value = None # unknown value is set to missing
else:
# anything else is forced to string/unicode
value = u(value, self.encoding, self.encodingErrors)
value = value.strip()
record.append(value)
return record
def record(self, i=0):
"""Returns a specific dbf record based on the supplied index."""
f = self.__getFileObj(self.dbf)
if self.numRecords is None:
self.__dbfHeader()
i = self.__restrictIndex(i)
recSize = self.__recStruct.size
f.seek(0)
f.seek(self.__dbfHdrLength + (i * recSize))
return self.__record()
def records(self):
"""Returns all records in a dbf file."""
if self.numRecords is None:
self.__dbfHeader()
records = []
f = self.__getFileObj(self.dbf)
f.seek(self.__dbfHdrLength)
for i in range(self.numRecords):
r = self.__record()
if r:
records.append(r)
return records
def iterRecords(self):
"""Serves up records in a dbf file as an iterator.
Useful for large shapefiles or dbf files."""
if self.numRecords is None:
self.__dbfHeader()
f = self.__getFileObj(self.dbf)
f.seek(self.__dbfHdrLength)
for i in xrange(self.numRecords):
r = self.__record()
if r:
yield r
def shapeRecord(self, i=0):
"""Returns a combination geometry and attribute record for the
supplied record index."""
i = self.__restrictIndex(i)
return ShapeRecord(shape=self.shape(i), record=self.record(i))
def shapeRecords(self):
"""Returns a list of combination geometry/attribute records for
all records in a shapefile."""
shapeRecords = []
return [ShapeRecord(shape=rec[0], record=rec[1]) \
for rec in zip(self.shapes(), self.records())]
def iterShapeRecords(self):
"""Returns a generator of combination geometry/attribute records for
all records in a shapefile."""
for shape, record in izip(self.iterShapes(), self.iterRecords()):
yield ShapeRecord(shape=shape, record=record)class Writer: """Provides write support for ESRI Shapefiles.""" def init(self, shapeType=None, autoBalance=False, bufsize=None, **kwargs): self.autoBalance = autoBalance self.fields = [] self.shapeType = shapeType self.shp = None self.shx = None self.dbf = None
Create temporary files for immediate writing, minus the header
self.bufsize = bufsize or 1056*1000*100 # default is 100 mb
self._shp = tempfile.TemporaryFile()
self._shx = tempfile.TemporaryFile()
self._dbf = tempfile.TemporaryFile()
# Geometry record offsets and lengths for writing shx file.
self.recNum = 0
self.shpNum = 0
self._bbox = [0,0,0,0]
self._zbox = [0,0]
self._mbox = [0,0]
# Use deletion flags in dbf? Default is false (0).
self.deletionFlag = 0
# Encoding
self.encoding = kwargs.pop('encoding', 'utf-8')
self.encodingErrors = kwargs.pop('encodingErrors', 'strict')
def __len__(self):
"""Returns the current number of features written to the shapefile.
If shapes and records are unbalanced, the length is considered the highest
of the two."""
return max(self.recNum, self.shpNum)
def __getFileObj(self, f):
"""Safety handler to verify file-like objects"""
if not f:
raise ShapefileException("No file-like object available.")
elif hasattr(f, "write"):
return f
else:
pth = os.path.split(f)[0]
if pth and not os.path.exists(pth):
os.makedirs(pth)
return open(f, "wb")
def __shpFileLength(self):
"""Calculates the file length of the shp file."""
# Start with header length
size = 100
# Calculate size of all shapes
self._shp.seek(0,2)
size += self._shp.tell()
# Calculate size as 16-bit words
size //= 2
return size
def __bbox(self, s):
x = []
y = []
if len(s.points) > 0:
px, py = list(zip(*s.points))[:2]
x.extend(px)
y.extend(py)
if len(x) == 0:
return [0] * 4
bbox = [min(x), min(y), max(x), max(y)]
# update global
self._bbox = [min(bbox[0],self._bbox[0]), min(bbox[1],self._bbox[1]), max(bbox[2],self._bbox[2]), max(bbox[3],self._bbox[3])]
return bbox
def __zbox(self, s):
z = []
try:
for p in s.points:
z.append(p[2])
except IndexError:
pass
if not z: z.append(0)
zbox = [min(z), max(z)]
# update global
self._zbox = [min(zbox[0],self._zbox[0]), min(zbox[1],self._zbox[1]), max(zbox[2],self._zbox[2]), max(zbox[3],self._zbox[3])]
return zbox
def __mbox(self, shapes):
m = []
try:
for p in s.points:
m.append(p[3])
except IndexError:
pass
if not m: m.append(0)
mbox = [min(m), max(m)]
# update global
self._mbox = [min(mbox[0],self._mbox[0]), min(mbox[1],self._mbox[1]), max(mbox[2],self._mbox[2]), max(mbox[3],self._mbox[3])]
return mbox
def bbox(self):
"""Returns the current bounding box for the shapefile which is
the lower-left and upper-right corners. It does not contain the
elevation or measure extremes."""
return self._bbox
def zbox(self):
"""Returns the current z extremes for the shapefile."""
return self._zbox
def mbox(self):
"""Returns the current m extremes for the shapefile."""
return self._mbox
def __shapefileHeader(self, fileObj, headerType='shp'):
"""Writes the specified header type to the specified file-like object.
Several of the shapefile formats are so similar that a single generic
method to read or write them is warranted."""
f = self.__getFileObj(fileObj)
f.seek(0)
# File code, Unused bytes
f.write(pack(">6i", 9994,0,0,0,0,0))
# File length (Bytes / 2 = 16-bit words)
if headerType == 'shp':
f.write(pack(">i", self.__shpFileLength()))
elif headerType == 'shx':
f.write(pack('>i', ((100 + (self.shpNum * 8)) // 2)))
# Version, Shape type
if self.shapeType is None:
self.shapeType = NULL
f.write(pack("<2i", 1000, self.shapeType))
# The shapefile's bounding box (lower left, upper right)
if self.shapeType != 0:
try:
f.write(pack("<4d", *self.bbox()))
except error:
raise ShapefileException("Failed to write shapefile bounding box. Floats required.")
else:
f.write(pack("<4d", 0,0,0,0))
# Elevation
z = self.zbox()
# Measure
m = self.mbox()
try:
f.write(pack("<4d", z[0], z[1], m[0], m[1]))
except error:
raise ShapefileException("Failed to write shapefile elevation and measure values. Floats required.")
def __dbfHeader(self):
"""Writes the dbf header and field descriptors."""
f = self.__getFileObj(self.dbf)
f.seek(0)
version = 3
year, month, day = time.localtime()[:3]
year -= 1900
# Remove deletion flag placeholder from fields
for field in self.fields:
if str(field[0]).startswith("Deletion"):
self.fields.remove(field)
numRecs = self.recNum
numFields = len(self.fields)
headerLength = numFields * 32 + 33
recordLength = sum([int(field[2]) for field in self.fields]) + 1
header = pack('<BBBBLHH20x', version, year, month, day, numRecs,
headerLength, recordLength)
f.write(header)
# Field descriptors
for field in self.fields:
name, fieldType, size, decimal = field
name = b(name, 'ascii', self.encodingErrors)
name = name.replace(b' ', b'_')
name = name.ljust(11).replace(b' ', b'\x00')
fieldType = b(fieldType, 'ascii', self.encodingErrors)
size = int(size)
fld = pack('<11sc4xBB14x', name, fieldType, size, decimal)
f.write(fld)
# Terminator
f.write(b'\r')
def shape(self, s):
# Balance if already not balanced
if self.autoBalance and self.recNum < self.shpNum:
self.balance()
# Check is shape or import from geojson
if not isinstance(s, Shape):
if hasattr(s, "__geo_interface__"):
s = s.__geo_interface__
if isinstance(s, dict):
s = geojson_to_shape(s)
else:
raise Exception("Can only write Shape objects, GeoJSON dictionaries, "
"or objects with the __geo_interface__, "
"not: %r" % s)
# Write to file
offset,length = self.__shpRecord(s)
self.__shxRecord(offset, length)
def __shpRecord(self, s):
f = self.__getFileObj(self._shp)
offset = 100 + f.tell()
# Record number, Content length place holder
f.write(pack(">2i", self.shpNum, 0))
self.shpNum += 1
start = f.tell()
# Shape Type
if self.shapeType is None and s.shapeType != NULL:
self.shapeType = s.shapeType
if self.shapeType != 31 and s.shapeType != NULL and s.shapeType != self.shapeType:
raise Exception("The shape's type (%s) must match the type of the shapefile (%s)." % (s.shapeType, self.shapeType))
f.write(pack("<i", s.shapeType))
# All shape types capable of having a bounding box
if s.shapeType in (3,5,8,13,15,18,23,25,28,31):
try:
f.write(pack("<4d", *self.__bbox(s)))
except error:
raise ShapefileException("Falied to write bounding box for record %s. Expected floats." % recNum)
# Shape types with parts
if s.shapeType in (3,5,13,15,23,25,31):
# Number of parts
f.write(pack("<i", len(s.parts)))
# Shape types with multiple points per record
if s.shapeType in (3,5,8,13,15,23,25,31):
# Number of points
f.write(pack("<i", len(s.points)))
# Write part indexes
if s.shapeType in (3,5,13,15,23,25,31):
for p in s.parts:
f.write(pack("<i", p))
# Part types for Multipatch (31)
if s.shapeType == 31:
for pt in s.partTypes:
f.write(pack("<i", pt))
# Write points for multiple-point records
if s.shapeType in (3,5,8,13,15,23,25,31):
try:
[f.write(pack("<2d", *p[:2])) for p in s.points]
except error:
raise ShapefileException("Failed to write points for record %s. Expected floats." % recNum)
# Write z extremes and values
if s.shapeType in (13,15,18,31):
try:
f.write(pack("<2d", *self.__zbox(s)))
except error:
raise ShapefileException("Failed to write elevation extremes for record %s. Expected floats." % recNum)
try:
if hasattr(s,"z"):
f.write(pack("<%sd" % len(s.z), *s.z))
else:
[f.write(pack("<d", p[2])) for p in s.points]
except error:
raise ShapefileException("Failed to write elevation values for record %s. Expected floats." % recNum)
# Write m extremes and values
if s.shapeType in (13,15,18,23,25,28,31):
try:
if hasattr(s,"m") and None not in s.m:
f.write(pack("<%sd" % len(s.m), *s.m))
else:
f.write(pack("<2d", *self.__mbox(s)))
except error:
raise ShapefileException("Failed to write measure extremes for record %s. Expected floats" % recNum)
try:
[f.write(pack("<d", len(p) > 3 and p[3] or 0)) for p in s.points]
except error:
raise ShapefileException("Failed to write measure values for record %s. Expected floats" % recNum)
# Write a single point
if s.shapeType in (1,11,21):
try:
f.write(pack("<2d", s.points[0][0], s.points[0][1]))
except error:
raise ShapefileException("Failed to write point for record %s. Expected floats." % recNum)
# Write a single Z value
if s.shapeType == 11:
if hasattr(s, "z"):
try:
if not s.z:
s.z = (0,)
f.write(pack("<d", s.z[0]))
except error:
raise ShapefileException("Failed to write elevation value for record %s. Expected floats." % recNum)
else:
try:
if len(s.points[0])<3:
s.points[0].append(0)
f.write(pack("<d", s.points[0][2]))
except error:
raise ShapefileException("Failed to write elevation value for record %s. Expected floats." % recNum)
# Write a single M value
if s.shapeType in (11,21):
if hasattr(s, "m"):
try:
if not s.m:
s.m = (0,)
f.write(pack("<1d", s.m[0]))
except error:
raise ShapefileException("Failed to write measure value for record %s. Expected floats." % recNum)
else:
try:
if len(s.points[0])<4:
s.points[0].append(0)
f.write(pack("<1d", s.points[0][3]))
except error:
raise ShapefileException("Failed to write measure value for record %s. Expected floats." % recNum)
# Finalize record length as 16-bit words
finish = f.tell()
length = (finish - start) // 2
# start - 4 bytes is the content length field
f.seek(start-4)
f.write(pack(">i", length))
f.seek(finish)
return offset,length
def __shxRecord(self, offset, length):
"""Writes the shx records."""
f = self.__getFileObj(self._shx)
f.write(pack(">i", offset // 2))
f.write(pack(">i", length))
def record(self, *recordList, **recordDict):
"""Creates a dbf attribute record. You can submit either a sequence of
field values or keyword arguments of field names and values. Before
adding records you must add fields for the record values using the
fields() method. If the record values exceed the number of fields the
extra ones won't be added. In the case of using keyword arguments to specify
field/value pairs only fields matching the already registered fields
will be added."""
# Balance if already not balanced
if self.autoBalance and self.recNum > self.shpNum:
self.balance()
record = []
fieldCount = len(self.fields)
# Compensate for deletion flag
if self.fields[0][0].startswith("Deletion"): fieldCount -= 1
if recordList:
record = [recordList[i] for i in range(fieldCount)]
elif recordDict:
for field in self.fields:
if field[0] in recordDict:
val = recordDict[field[0]]
if val is None:
record.append("")
else:
record.append(val)
else:
# Blank fields for empty record
record = ["" for i in range(fieldCount)]
self.__dbfRecord(record)
def __dbfRecord(self, record):
"""Writes the dbf records."""
f = self.__getFileObj(self._dbf)
self.recNum += 1
if not self.fields[0][0].startswith("Deletion"):
f.write(b' ') # deletion flag
for (fieldName, fieldType, size, deci), value in zip(self.fields, record):
fieldType = fieldType.upper()
size = int(size)
if fieldType in ("N","F"):
# numeric or float: number stored as a string, right justified, and padded with blanks to the width of the field.
if value in MISSING:
value = b"*"*size # QGIS NULL
elif not deci:
# force to int
try:
# first try to force directly to int.
# forcing a large int to float and back to int
# will lose information and result in wrong nr.
value = int(value)
except ValueError:
# forcing directly to int failed, so was probably a float.
value = int(float(value))
value = format(value, "d")[:size].rjust(size) # caps the size if exceeds the field size
else:
value = float(value)
value = format(value, ".%sf"%deci)[:size].rjust(size) # caps the size if exceeds the field size
elif fieldType == "D":
# date: 8 bytes - date stored as a string in the format YYYYMMDD.
if isinstance(value, date):
value = value.strftime("%Y%m%d")
elif isinstance(value, list) and len(value) == 3:
value = date(*value).strftime("%Y%m%d")
elif value in MISSING:
value = b'0' * 8 # QGIS NULL for date type
elif is_string(value) and len(value) == 8:
pass # value is already a date string
else:
raise ShapefileException("Date values must be either a datetime.date object, a list, a YYYYMMDD string, or a missing value.")
elif fieldType == 'L':
# logical: 1 byte - initialized to 0x20 (space) otherwise T or F.
if value in MISSING:
value = b' ' # missing is set to space
elif value in [True,1]:
value = b'T'
elif value in [False,0]:
value = b'F'
else:
value = b' ' # unknown is set to space
else:
# anything else is forced to string, truncated to the length of the field
value = b(value, self.encoding, self.encodingErrors)[:size].ljust(size)
if not isinstance(value, bytes):
# just in case some of the numeric format() and date strftime() results are still in unicode (Python 3 only)
value = b(value, 'ascii', self.encodingErrors) # should be default ascii encoding
if len(value) != size:
raise ShapefileException(
"Shapefile Writer unable to pack incorrect sized value"
" (size %d) into field '%s' (size %d)." % (len(value), fieldName, size))
f.write(value)
def balance(self):
"""Adds corresponding empty attributes or null geometry records depending
on which type of record was created to make sure all three files
are in synch."""
while self.recNum > self.shpNum:
self.null()
while self.recNum < self.shpNum:
self.record()
def null(self):
"""Creates a null shape."""
self.shape(Shape(NULL))
def point(self, x, y, z=0, m=0, shapeType=POINT):
"""Creates a point shape."""
pointShape = Shape(shapeType)
if shapeType == POINT:
pointShape.points.append([x, y])
elif shapeType == POINTZ:
pointShape.points.append([x, y, z])
elif shapeType == POINTM:
pointShape.points.append([x, y, z, m])
self.shape(pointShape)
def line(self, parts=[], shapeType=POLYLINE):
"""Creates a line shape. This method is just a convienience method
which wraps 'poly()'.
"""
self.poly(parts, shapeType, [])
def poly(self, parts=[], shapeType=POLYGON, partTypes=[]):
"""Creates a shape that has multiple collections of points (parts)
including lines, polygons, and even multipoint shapes. If no shape type
is specified it defaults to 'polygon'. If no part types are specified
(which they normally won't be) then all parts default to the shape type.
"""
polyShape = Shape(shapeType)
polyShape.parts = []
polyShape.points = []
# Make sure polygons are closed
if shapeType in (5,15,25,31):
for part in parts:
if part[0] != part[-1]:
part.append(part[0])
for part in parts:
polyShape.parts.append(len(polyShape.points))
for point in part:
# Ensure point is list
if not isinstance(point, list):
point = list(point)
# Make sure point has z and m values
while len(point) < 4:
point.append(0)
polyShape.points.append(point)
if polyShape.shapeType == 31:
if not partTypes:
for part in parts:
partTypes.append(polyShape.shapeType)
polyShape.partTypes = partTypes
self.shape(polyShape)
def field(self, name, fieldType="C", size="50", decimal=0):
"""Adds a dbf field descriptor to the shapefile."""
if fieldType == "D":
size = "8"
decimal = 0
elif fieldType == "L":
size = "1"
decimal = 0
self.fields.append((name, fieldType, size, decimal))
def saveShp(self, target):
"""Save an shp file."""
if not hasattr(target, "write"):
target = os.path.splitext(target)[0] + '.shp'
self.shp = self.__getFileObj(target)
self.__shapefileHeader(self.shp, headerType='shp')
self.shp.seek(100)
self._shp.seek(0)
chunk = True
while chunk:
chunk = self._shp.read(self.bufsize)
self.shp.write(chunk)
def saveShx(self, target):
"""Save an shx file."""
if not hasattr(target, "write"):
target = os.path.splitext(target)[0] + '.shx'
self.shx = self.__getFileObj(target)
self.__shapefileHeader(self.shx, headerType='shx')
self.shx.seek(100)
self._shx.seek(0)
chunk = True
while chunk:
chunk = self._shx.read(self.bufsize)
self.shx.write(chunk)
def saveDbf(self, target):
"""Save a dbf file."""
if not hasattr(target, "write"):
target = os.path.splitext(target)[0] + '.dbf'
self.dbf = self.__getFileObj(target)
self.__dbfHeader() # writes to .dbf
self._dbf.seek(0)
chunk = True
while chunk:
chunk = self._dbf.read(self.bufsize)
self.dbf.write(chunk)
def save(self, target=None, shp=None, shx=None, dbf=None):
"""Save the shapefile data to three files or
three file-like objects. SHP and DBF files can also
be written exclusively using saveShp, saveShx, and saveDbf respectively.
If target is specified but not shp, shx, or dbf then the target path and
file name are used. If no options or specified, a unique base file name
is generated to save the files and the base file name is returned as a
string.
"""
# Balance if already not balanced
if shp and dbf:
if self.autoBalance:
self.balance()
if self.recNum != self.shpNum:
raise ShapefileException("When saving both the dbf and shp file, "
"the number of records (%s) must correspond "
"with the number of shapes (%s)" % (self.recNum, self.shpNum))
# Save
if shp:
self.saveShp(shp)
if shx:
self.saveShx(shx)
if dbf:
self.saveDbf(dbf)
# Create a unique file name if one is not defined
if not shp and not shx and not dbf:
generated = False
if not target:
temp = tempfile.NamedTemporaryFile(prefix="shapefile_",dir=os.getcwd())
target = temp.name
generated = True
self.saveShp(target)
self.shp.close()
self.saveShx(target)
self.shx.close()
self.saveDbf(target)
self.dbf.close()
if generated:
return targetBegin Testing
def test(**kwargs): import doctest doctest.NORMALIZE_WHITESPACE = 1 verbosity = kwargs.get('verbose', 0) if verbosity == 0: print('Running doctests...')
# ignore py2-3 unicode differences
import re
class Py23DocChecker(doctest.OutputChecker):
def check_output(self, want, got, optionflags):
if sys.version_info[0] == 2:
got = re.sub("u'(.*?)'", "'\\1'", got)
got = re.sub('u"(.*?)"', '"\\1"', got)
res = doctest.OutputChecker.check_output(self, want, got, optionflags)
return res
def summarize(self):
doctest.OutputChecker.summarize(True)
# run tests
runner = doctest.DocTestRunner(checker=Py23DocChecker(), verbose=verbosity)
with open("README.md","rb") as fobj:
test = doctest.DocTestParser().get_doctest(string=fobj.read().decode("utf8"), globs={}, name="README", filename="README.md", lineno=0)
failure_count, test_count = runner.run(test)
# print results
if verbosity:
runner.summarize(True)
else:
if failure_count == 0:
print('All test passed successfully')
elif failure_count > 0:
runner.summarize(verbosity)
return failure_countif name == "main": """ Doctests are contained in the file 'README.md', and are tested using the built-in testing libraries. """ failure_count = test() sys.exit(failure_count)
shCampos
jayaBalaR
karimbahgat
Hi I'm working with Anaconda and Python 2.7, and I installed pyshp using
conda-forge. To test, I imported the library like this:import pyshpHowever, the following error appeared:
ImportError: No module named pyshpBut when I do this:
import shapefileno errors appear. Just to test, I uninstalled the library and reinstalled using
pip, but the same thing happens. I really need to importpyshp, because withshapefilemy code does not run (I also do not know the reason).Thanks for the help :)