numpy.all#
- numpy.all(a,axis=None,out=None,keepdims=<novalue>,*,where=<novalue>)[source]#
Test whether all array elements along a given axis evaluate to True.
- Parameters:
- aarray_like
Input array or object that can be converted to an array.
- axisNone or int or tuple of ints, optional
Axis or axes along which a logical AND reduction is performed.The default (
axis=None) is to perform a logical AND over allthe dimensions of the input array.axis may be negative, inwhich case it counts from the last to the first axis. If thisis a tuple of ints, a reduction is performed on multipleaxes, instead of a single axis or all the axes as before.- outndarray, optional
Alternate output array in which to place the result.It must have the same shape as the expected output and itstype is preserved (e.g., if
dtype(out)is float, the resultwill consist of 0.0’s and 1.0’s). SeeOutput type determinationfor more details.- keepdimsbool, optional
If this is set to True, the axes which are reduced are leftin the result as dimensions with size one. With this option,the result will broadcast correctly against the input array.
If the default value is passed, thenkeepdims will not bepassed through to the
allmethod of sub-classes ofndarray, however any non-default value will be. If thesub-class’ method does not implementkeepdims anyexceptions will be raised.- wherearray_like of bool, optional
Elements to include in checking for allTrue values.See
reducefor details.New in version 1.20.0.
- Returns:
- allndarray, bool
A new boolean or array is returned unlessout is specified,in which case a reference toout is returned.
See also
ndarray.allequivalent method
anyTest whether any element along a given axis evaluates to True.
Notes
Not a Number (NaN), positive infinity and negative infinityevaluate toTrue because these are not equal to zero.
Changed in version 2.0:Before NumPy 2.0,
alldid not return booleans for object dtypeinput arrays.This behavior is still available vianp.logical_and.reduce.Examples
>>>importnumpyasnp>>>np.all([[True,False],[True,True]])False
>>>np.all([[True,False],[True,True]],axis=0)array([ True, False])
>>>np.all([-1,4,5])True
>>>np.all([1.0,np.nan])True
>>>np.all([[True,True],[False,True]],where=[[True],[False]])True
>>>o=np.array(False)>>>z=np.all([-1,4,5],out=o)>>>id(z),id(o),z(28293632, 28293632, array(True)) # may vary