Show how to write to file in examples

[fedderw]

It's not obvious to all programmers (me) how to get the output from the writer object to, say, a markdown file.

[hugovk]

You can use writer.dump:

https://pytablewriter.readthedocs.io/en/latest/pages/reference/writers/text/markup/md.html?highlight=MarkdownTableWriter#pytablewriter.MarkdownTableWriter.dump

So adding to the example at https://pytablewriter.readthedocs.io/en/latest/pages/examples/table_format/text/markdown.html:

from pytablewriter import MarkdownTableWriter

def main():
    writer = MarkdownTableWriter(
        table_name="example_table",
        headers=["int", "float", "str", "bool", "mix", "time"],
        value_matrix=[
            [0,   0.1,      "hoge", True,   0,      "2017-01-01 03:04:05+0900"],
            [2,   "-2.23",  "foo",  False,  None,   "2017-12-23 45:01:23+0900"],
            [3,   0,        "bar",  "true",  "inf", "2017-03-03 33:44:55+0900"],
            [-10, -9.9,     "",     "FALSE", "nan", "2017-01-01 00:00:00+0900"],
        ],
    )
    writer.write_table()
    writer.dump("my_markdown.md")

if __name__ == "__main__":
    main()

And then my_markdown.md contains:

# example_table
|int|float|str |bool |  mix   |          time          |
|--:|----:|----|-----|-------:|------------------------|
|  0| 0.10|hoge|True |       0|2017-01-01 03:04:05+0900|
|  2|-2.23|foo |False|        |2017-12-23 45:01:23+0900|
|  3| 0.00|bar |True |Infinity|2017-03-03 33:44:55+0900|
|-10|-9.90|    |False|     NaN|2017-01-01 00:00:00+0900|

[fedderw]

Oh ok, awesome, thanks! Can I write any string to the writer object?

[hugovk]

Yes, the first parameter to writer.dump can be whatever filename you like (or an output stream):

output – The value must either an output stream or a path to an output file.

https://pytablewriter.readthedocs.io/en/latest/pages/reference/writers/text/markup/md.html?highlight=MarkdownTableWriter#pytablewriter.MarkdownTableWriter.dump

[thombashi]

@fedderw Thank you for your feedback, I had added a link to an example usage to the README: https://github.com/thombashi/pytablewriter#write-a-markdown-table-to-a-stream-or-a-file

@hugovk Thank you for your answer.

[PabloPeso]

Is it possible to use dump to append the table to an existing file? I think at the moment it is overwriting by default. Thanks

[thombashi]

@PabloPeso This is possible with code like the following:

from pytablewriter import MarkdownTableWriter

def main():
    writer = MarkdownTableWriter(
        table_name="example_table",
        headers=["int", "float", "str", "bool", "mix", "time"],
        value_matrix=[
            [0,   0.1,      "hoge", True,   0,      "2017-01-01 03:04:05+0900"],
            [2,   "-2.23",  "foo",  False,  None,   "2017-12-23 45:01:23+0900"],
            [3,   0,        "bar",  "true",  "inf", "2017-03-03 33:44:55+0900"],
            [-10, -9.9,     "",     "FALSE", "nan", "2017-01-01 00:00:00+0900"],
        ],
    )
    writer.write_table()
    with open("my_markdown.md", "a") as f:
        writer.dump(f)

if __name__ == "__main__":
    main()