def is_version_locked(requirement):
    """
    Check if requirement's specifers lock package to single version
    (f.ex. "django==1.7.0") or bounded range (f.ex "django>=1.7,<1.8").
    :param requirement:
    :type: pip.req.req_install.InstallRequirement
    :rtype: bool
    """
    for spec in requirement.specifier:
        if spec.operator in ('==', '<', '<='):
            return True
    return False
