Is ‘file’ a keyword in python?

No, file is not a keyword:

>>> import keyword
>>> keyword.iskeyword('file')
False

The name is not present in Python 3. In Python 2, file is a built-in:

>>> import __builtin__, sys
>>> hasattr(__builtin__, 'file')
True
>>> sys.version_info[:2]
(2, 7)

It can be seen as an alias for open(), but it was removed in Python 3, where the new io framework replaced it. Technically, it is the type of object returned by the Python 2 open() function.