is_snake_case_package_name

stringtools.is_snake_case_package_name(expr)

Is true when expr is a string and is underscore-delimited lowercase package name.

>>> stringtools.is_snake_case_package_name('foo.bar.blah_package')
True

Otherwise false:

>>> stringtools.is_snake_case_package_name('foo.bar.BlahPackage')
False

Returns true or false.