def prepend_line(filepath, line):
with open(filepath) as f:<EOL><INDENT>lines = f.readlines()<EOL><DEDENT>lines.insert(<NUM_LIT:0>, line)<EOL>with open(filepath, '<STR_LIT:w>') as f:<EOL><INDENT>f.writelines(lines)<EOL><DEDENT>
Rewrite a file adding a line to its beginning.