10 Neat Python Tricks Beginners Should Know

Trick #1

Reversing a string in Python

>>> a =  "codementor"
>>> print "Reverse is",a[::-1]
Reverse is rotnemedoc

Trick #2

Transposing a Matrix

>>> mat = [[1, 2, 3], [4, 5, 6]]
>>> zip(*mat)
[(1, 4), (2, 5), (3, 6)]

Trick #3

a = [1,2,3]

Store all three values of the list in 3 new variables

>>> a = [1, 2, 3]
>>> x, y, z = a 
>>> x
1
>>> y
2
>>> z
3

Trick #4

a = ["Code", "mentor", "Python", "Developer"]

Create a single string from all the elements in list above.

>>> print " ".join(a)
Code mentor Python Developer

Trick #5

List 1 = ['a', 'b', 'c', 'd']

List 2 = ['p', 'q', 'r', 's']

Write a Python code to print

• ap
• bq
• cr
• ds

>>> for x, y in zip(list1,list2):
...    print x, y
...
a p
b q
c r
d s

Trick #6

Swap two numbers with one line of code.

>>> a=7
>>> b=5
>>> b, a =a, b
>>> a
5
>>> b
7

Trick #7

Print "codecodecodecode mentormentormentormentormentor" without using loops

>>> print "code"*4+' '+"mentor"*5
codecodecodecode mentormentormentormentormentor

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]

>>> import itertools 
>>> list(itertools.chain.from_iterable(a))
[1, 2, 3, 4, 5, 6]

Trick #9

Checking if two words are anagrams

def is_anagram(word1, word2):
    """Checks whether the words are anagrams.
    word1: string
    word2: string
    returns: boolean
    """

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

from collections import Counter
def is_anagram(str1, str2):
     return Counter(str1) == Counter(str2)
>>> is_anagram('abcd','dbca')
True
>>> is_anagram('abcd','dbaa')
False

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.

>>> result = map(lambda x:int(x) ,raw_input().split())
1 2 3 4
>>> result
[1, 2, 3, 4]