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numpy.core.defchararray.index
numpy.core.defchararray.index(a, sub, start=0, end=None)[source]- 
    
Like
find, but raisesValueErrorwhen the substring is not found.Calls
str.indexelement-wise.Parameters: - 
           
a : array_like of str or unicode - 
           
sub : str or unicode - 
           
start, end : int, optional 
Returns: - 
           
out : ndarray - 
           
Output array of ints. Returns -1 if
subis not found. 
 - 
           
 
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 https://docs.scipy.org/doc/numpy-1.16.1/reference/generated/numpy.core.defchararray.index.html