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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

Python: Cache results with decorators

There is a great way to cache functions with decorators in Python. Caching will help save time and precious resources when there is an expensive function at hand.

Implementation is easy, just import lru_cache from functools library and decorate your function using @lru_cache.

from functools import lru_cache

@lru_cache(maxsize=None)
def fibo(a):
    if a <= 1:
        return a
    else:
        return fibo(a-1) + fibo(a-2)

for i in range(20):
    print(fibo(i), end="|")

print("\n\n", fibo.cache_info())

Output:

0|1|1|2|3|5|8|13|21|34|55|89|144|233|377|610|987|1597|2584|4181|

 CacheInfo(hits=36, misses=20, maxsize=None, currsize=20)