numpy.extract (condition, array): Returns input_array elements if they satisfy some specified condition.
array: Input array. User apply conditions on input_array elements condition: [array_like] Condition on the basis of which user extract elements. Applying condition on input_array, if we print condition, it will return an array filled with either True or False. Array elements are extracted from the Indices having True value.
Array elements that satisfy the condition.
Original array: [[0 1] [2 3] [4 5] [6 7] [8 9]] Array Condition a: [[False True] [True True] [False True] [True True] [False True]] Elements that satisfy condition a: [1 2 3 5 6 7 9] Array Condition b: [[False False] [False False] [False True] [ False False] [False False]] Elements that satisfy condition b: 
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This article is courtesy of Mohit Gupta_OMG