check_whitespace.py 文件源码

def get_correct_indentation_diff(code, filename):
    """
    Generate a diff to make code correctly indented.

    :param code: a string containing a file's worth of Python code
    :param filename: the filename being considered (used in diff generation only)
    :returns: a unified diff to make code correctly indented, or
              None if code is already correctedly indented
    """
    code_buffer = StringIO(code)
    output_buffer = StringIO()
    reindenter = reindent.Reindenter(code_buffer)
    reindenter.run()
    reindenter.write(output_buffer)
    reindent_output = output_buffer.getvalue()
    output_buffer.close()
    if code != reindent_output:
        diff_generator = difflib.unified_diff(code.splitlines(True), reindent_output.splitlines(True),
                                              fromfile=filename, tofile=filename + " (reindented)")
        # work around http://bugs.python.org/issue2142
        diff_tuple = map(clean_diff_line_for_python_bug_2142, diff_generator)
        diff = "".join(diff_tuple)
        return diff
    else:
        return None