10 Amazing Python Tricks You Should Know

May 15, 2018 Leave a Comment
These 10 Python programming tricks by Sumit Raj of CodeMentor[1] amazed me:


I’d happily like to share them here by courtesy Sumit Raj:
Trick #1
Reversing a string in Python
    

  1. >>> a =  "codementor"
    2. 

  2. >>> print "Reverse is",a[::-1]
    3. 

  3. Reverse is rotnemedoc
    4.
Trick #2
Transposing a Matrix
    

  1. >>> mat = [[1, 2, 3], [4, 5, 6]]
    2. 

  2. >>> zip(*mat)
    3. 

  3. [(1, 4), (2, 5), (3, 6)]
    4.
Trick #3
a = [1,2,3]
Store all three values of the list in 3 new variables
    

  1. >>> a = [1, 2, 3]
    2. 

  2. >>> x, y, z = a 
    3. 

  3. >>> x
    4. 

  4. 1
    5. 

  5. >>> y
    6. 

  6. 2
    7. 

  7. >>> z
    8. 

  8. 3
    9.
Trick #4
a = ["Code", "mentor", "Python", "Developer"]
Create a single string from all the elements in list above.
    

  1. >>> print " ".join(a)
    2. 

  2. Code mentor Python Developer
    3.
Trick #5
List 1 = ['a', 'b', 'c', 'd']
List 2 = ['p', 'q', 'r', 's']
Write a Python code to print
  • ap
  • bq
  • cr
  • ds
    

  1. >>> for x, y in zip(list1,list2):
    2. 

  2. ...    print x, y
    3. 

  3. ...
    4. 

  4. a p
    5. 

  5. b q
    6. 

  6. c r
    7. 

  7. d s
    8.
Trick #6
Swap two numbers with one line of code.
    

  1. >>> a=7
    2. 

  2. >>> b=5
    3. 

  3. >>> b, a =a, b
    4. 

  4. >>> a
    5. 

  5. 5
    6. 

  6. >>> b
    7. 

  7. 7
    8.
Trick #7
Print "codecodecodecode mentormentormentormentormentor" without using loops
    

  1. >>> print "code"*4+' '+"mentor"*5
    2. 

  2. codecodecodecode mentormentormentormentormentor
    3.
Trick #8
a = [[1, 2], [3, 4], [5, 6]]
Convert it to a single list without using any loops.
Output:- [1, 2, 3, 4, 5, 6]
    

  1. >>> import itertools 
    2. 

  2. >>> list(itertools.chain.from_iterable(a))
    3. 

  3. [1, 2, 3, 4, 5, 6]
    4.
Trick #9
Checking if two words are anagrams
    

  1. def is_anagram(word1, word2):
    2. 

  2.     """Checks whether the words are anagrams.
    3. 

  3.     word1: string
    4. 

  4.     word2: string
    5. 

  5.     returns: boolean
    6. 

  6.     """
    7.
Complete the above method to find if two words are anagrams.
    

  1. from collections import Counter
    2. 

  2. def is_anagram(str1, str2):
    3. 

  3.      return Counter(str1) == Counter(str2)
    4. 

  4. >>> is_anagram('abcd','dbca')
    5. 

  5. True
    6. 

  6. >>> is_anagram('abcd','dbaa')
    7. 

  7. False
    8.
Trick #10.
Taking a string input.
For example "1 2 3 4" and return [1, 2, 3, 4]
Remember list being returned has integers in it.
Don't use more than one line of code.
    

  1. >>> result = map(lambda x:int(x) ,raw_input().split())
    2. 

  2. 1 2 3 4
    3. 

  3. >>> result
    4. 

  4. [1, 2, 3, 4]
    5.

Footnotes