NumPy strings.swapcase() – Change Case of Each Character

NumPy strings.swapcase()

The numpy.strings.swapcase() function returns an element-wise copy of the input string with uppercase characters converted to lowercase and vice versa.

Syntax

numpy.strings.swapcase(a)

Parameters

Parameter	Type	Description
a	array-like (StringDType, bytes_, or str_ dtype)	Input array containing strings.

Return Value

Returns an ndarray with the same type as the input, where all uppercase characters are converted to lowercase and vice versa.

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Examples

1. Swapping Case for a Single String

In this example, we will convert uppercase letters to lowercase and lowercase letters to uppercase for a single string.

import numpy as np

# Define a string
word = np.str_("Apple")

# Apply swapcase()
result = np.strings.swapcase(word)

# Print the result
print("Original:", word)
print("Swapped Case:", result)

Output:

Original: Apple
Swapped Case: aPPLE

2. Swapping Case for an Array of Strings

In this example, we will convert the case for multiple string elements in an array.

import numpy as np

# Define an array of strings
fruits = np.array(["Apple", "Banana", "Cherry"], dtype="U")

# Apply swapcase() to each element
swapped_fruits = np.strings.swapcase(fruits)

# Print the results
print("Original:", fruits)
print("Swapped Case:", swapped_fruits)

Output:

Original: ['Apple' 'Banana' 'Cherry']
Swapped Case: ['aPPLE' 'bANANA' 'cHERRY']

3. Swapping Case with Mixed Case Strings

In this example, we will show how mixed uppercase and lowercase letters are swapped.

import numpy as np

# Define an array of mixed-case strings
words = np.array(["PyThOn", "NuMPy", "CoDinG"], dtype="U")

# Apply swapcase()
swapped_words = np.strings.swapcase(words)

# Print the results
print("Original:", words)
print("Swapped Case:", swapped_words)

Output:

Original: ['PyThOn' 'NuMPy' 'CoDinG']
Swapped Case: ['pYtHoN' 'nUmpY' 'cOdINg']