environment/lib/python2.7/site-packages/IPython/parallel/controller/dependency.py
def _require(*names):
    """Helper for @require decorator."""
    from IPython.parallel.error import UnmetDependency
    user_ns = globals()
    for name in names:
        if name in user_ns:
            continue
        try:
            exec 'import %s'%name in user_ns
        except ImportError:
            raise UnmetDependency(name)
    return True
def _require(*names):
    """Helper for @require decorator."""
    from IPython.parallel.error import UnmetDependency
    user_ns = globals()
    for name in names:
        if name in user_ns:
            continue
        try:
            exec 'import %s'%name in user_ns
        except ImportError:
            raise UnmetDependency(name)
    return True
Helper for @require decorator.