numpy.alen() in Python Last Updated : 28 Dec, 2018 Comments Improve Suggest changes Like Article Like Report numpy.alen() function is used to return the length of the first dimension of the input array. Syntax : numpy.alen(arr) Parameters : arr : [array_like] Input array. Return : [int]Length of the first dimension of arr. Code #1 : Python3 # Python program explaining # alen() function import numpy as geek # input array(2 * 3) in_arr = geek.array([[ 2, 0, 7], [ 0, 5, 9]]) print ("Input array : ", in_arr) out_dim = geek.alen(in_arr) print ("Length of the first dimension of arr: ", out_dim) Output: Input array : [[2, 0, 7], [0, 5, 9]] Length of the first dimension of arr: 2 Code #2 : Python3 # Python program explaining # alen() function import numpy as geek # input array(1 * 3*3) in_arr = geek.arange(9).reshape(1, 3, 3) print ("Input array : \n", in_arr) out_dim = geek.alen(in_arr) print ("Length of the first dimension of arr: ", out_dim) Output: Input array : [[[0 1 2] [3 4 5] [6 7 8]]] Length of the first dimension of arr: 1 Comment More infoAdvertise with us Next Article numpy.alen() in Python J jana_sayantan Follow Improve Article Tags : Python Python-numpy Python numpy-arrayManipulation Practice Tags : python Similar Reads numpy.angle() in Python numpy.angle() function is used when we want to compute the angle of the complex argument. A complex number is represented by â x + yi " where x and y are real number and i= (-1)^1/2. The angle is calculated by the formula tan-1(x/y). Syntax : numpy.angle(z, deg=0) Parameters : z : [array_like] A com 2 min read numpy.arange() in Python numpy.arange() function creates an array of evenly spaced values within a given interval. It is similar to Python's built-in range() function but returns a NumPy array instead of a list. Let's understand with a simple example:Pythonimport numpy as np #create an array arr= np.arange(5 , 10) print(arr 2 min read numpy.find() in Python numpy.core.defchararray.find(arr, substring, start=0, end=None): Finds the lowest index of the sub-string in the specified range. Parameters: arr : array-like or string to be searched. substring : substring to search for. start, end : [int, optional] Range to search in. Returns : An integer array wi 1 min read numpy.index() in Python numpy.core.defchararray.index(arr, substring, start=0, end=None): Finds the lowest index of the sub-string in the specified range But if substring is not found, it raises ValueError. Parameters: arr : array-like or string to be searched. substring : substring to search for. start, end : [int, option 1 min read numpy.isnan() in Python The numpy.isnan() function tests element-wise whether it is NaN or not and returns the result as a boolean array. Syntax :Â numpy.isnan(array [, out]) Parameters :Â array : [array_like]Input array or object whose elements, we need to test for infinity out : [ndarray, optional]Output array placed wit 2 min read Like