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Python: Find palindromes in a given list of strings using Lambda

Python Lambda: Exercise-18 with Solution

Write a Python program to find palindromes in a given list of strings using Lambda.

According Wikipedia - A palindromic number or numeral palindrome is a number that remains the same when its digits are reversed. Like 16461, for example, it is "symmetrical". The term palindromic is derived from palindrome, which refers to a word (such as rotor or racecar) whose spelling is unchanged when its letters are reversed. The first 30 palindromic numbers (in decimal) are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202,...

Sample Solution:

Python Code :

texts = ["php", "w3r", "Python", "abcd", "Java", "aaa"]
print("Orginal list of strings:")
print(texts) 
result = list(filter(lambda x: (x == "".join(reversed(x))), texts)) 
print("\nList of palindromes:")
print(result)

Sample Output:

Orginal list of strings:
['php', 'w3r', 'Python', 'abcd', 'Java', 'aaa']

List of palindromes:
['php', 'aaa']

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Previous: Write a Python program to find the second lowest grade of any student(s) from the given names and grades of each student using lists and lambda.
Next: Write a Python program to find all anagrams of a string in a given list of strings using lambda.

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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