method
chararray.islower(self)
Returns true for each element if all cased characters in the string are lowercase and there is at least one cased character, false otherwise.
See also
char.islower
© 2005–2019 NumPy Developers
Licensed under the 3-clause BSD License.
https://docs.scipy.org/doc/numpy-1.17.0/reference/generated/numpy.char.chararray.islower.html