def isdigit(a):
return _vec_string(a, bool_, '<STR_LIT>')<EOL>
Returns true for each element if all characters in the string are
digits and there is at least one character, false otherwise.

Calls `str.isdigit` element-wise.

For 8-bit strings, this method is locale-dependent.

Parameters
----------
a : array_like of str or unicode

Returns
-------
out : ndarray
    Output array of bools

See also
--------
str.isdigit