def grep_one(srch_str, filepath):
for line in open(filepath):<EOL><INDENT>if srch_str in line:<EOL><INDENT>return line<EOL><DEDENT><DEDENT>return None<EOL>
Return the first line in file defined by filepath
    that contains srch_str

    Parameters
    ----------
    srch_str: str

    filepath: str

    Returns
    ----------
    str