def pip_install_requirements(requirements, constraints=None, **options):
    """Install a requirements file.

    :param constraints: Path to pip constraints file.
    http://pip.readthedocs.org/en/stable/user_guide/#constraints-files
    """
    command = ["install"]

    available_options = ('proxy', 'src', 'log', )
    for option in parse_options(options, available_options):
        command.append(option)

    command.append("-r {0}".format(requirements))
    if constraints:
        command.append("-c {0}".format(constraints))
        log("Installing from file: {} with constraints {} "
            "and options: {}".format(requirements, constraints, command))
    else:
        log("Installing from file: {} with options: {}".format(requirements,
                                                               command))
    pip_execute(command)
def pip_install_requirements ( requirements , constraints = None , ** options ) : command = [ "install" ] available_options = ( 'proxy' , 'src' , 'log' , ) for option in parse_options ( options , available_options ) : command . append ( option ) command . append ( "-r {0}" . format ( requirements ) ) if constraints : command . append ( "-c {0}" . format ( constraints ) ) log ( "Installing from file: {} with constraints {} " "and options: {}" . format ( requirements , constraints , command ) ) else : log ( "Installing from file: {} with options: {}" . format ( requirements , command ) ) pip_execute ( command )
Install a requirements file.

    :param constraints: Path to pip constraints file.
    http://pip.readthedocs.org/en/stable/user_guide/#constraints-files