from:
        http://cburgmer.posterous.com/pip-requirementstxt-and-setuppy

def parse_requirements(file_name):
    """
    from:
        http://cburgmer.posterous.com/pip-requirementstxt-and-setuppy
    """
    requirements = []
    with open(file_name, 'r') as f:
        for line in f:
            if re.match(r'(\s*#)|(\s*$)', line): continue
            if re.match(r'\s*-e\s+', line):
                requirements.append(re.sub(r'\s*-e\s+.*#egg=(.*)$',\
                        r'\1', line).strip())
            elif re.match(r'\s*-f\s+', line):
                pass
            else:
                requirements.append(line.strip())
    return requirements