Built-in 'file()' was removed in Python in favor of 'open()'

[cclauss]

open() will work as expected in both Python 2 and Python 3.

flake8 testing of https://github.com/NtesEyes/pylane on Python 3.7.1

$ flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

./pylane/shell/remote_shell.py:154:13: F821 undefined name 'file'
            file('/tmp/pmx-shell-log', 'w').write("%s\n%s" % (
            ^
1     F821 undefined name 'file'
1

E901,E999,F821,F822,F823 are the "showstopper" flake8 issues that can halt the runtime with a SyntaxError, NameError, etc. These 5 are different from most other flake8 issues which are merely "style violations" -- useful for readability but they do not effect runtime safety.

• F821: undefined name name
• F822: undefined name name in __all__
• F823: local variable name referenced before assignment
• E901: SyntaxError or IndentationError
• E999: SyntaxError -- failed to compile a file into an Abstract Syntax Tree