NumPy: Replace all numbers in a given array which is equal, less and greater to a given number

Last update on May 28 2022 12:54:46 (UTC/GMT +8 hours)

NumPy: Basic Exercise-54 with Solution

Write a NumPy program to replace all numbers in a given array which is equal, less and greater to a given number.

Sample Solution:

Python Code :

import numpy as np
nums = np.array([[5.54, 3.38, 7.99],
              [3.54, 8.32, 6.99],
              [1.54, 2.39, 9.29]])
print("Original array:")
print(nums)
n = 8.32
r = 18.32
print("\nReplace elements of the said array which are equal to ",n,"with",r)
print(np.where(nums == n, r, nums))
print("\nReplace elements with of the said array which are less than",n,"with",r)
print(np.where(nums < n, r, nums))
print("\nReplace elements with of the said array which are greater than",n,"with",r)
print(np.where(nums > n, r, nums))

Sample Output:

Original array:
[[5.54 3.38 7.99]
 [3.54 8.32 6.99]
 [1.54 2.39 9.29]]

Replace elements of the said array which are equal to  8.32 with 18.32
[[ 5.54  3.38  7.99]
 [ 3.54 18.32  6.99]
 [ 1.54  2.39  9.29]]

Replace elements with of the said array which are less than 8.32 with 18.32
[[18.32 18.32 18.32]
 [18.32  8.32 18.32]
 [18.32 18.32  9.29]]

Replace elements with of the said array which are greater than 8.32 with 18.32
[[ 5.54  3.38  7.99]
 [ 3.54  8.32  6.99]
 [ 1.54  2.39 18.32]]

Python-Numpy Code Editor:

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Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

The os and os.path modules.
The __file__ constant
os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
os.path.dirname(path) (returns "the directory name of pathname path")
os.getcwd() (returns "a string representing the current working directory")
os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m