Python One liners

This github repo is a collection of amazing python one liners which I regularly use which saved me a lot of time. Feel free to add more to the list.

Contents

• Sort a dictionary based on multiple conditions
• Thousand Separator
• Multiply all elements of a list
• Flatten a List
• Remove duplicate elements from a list
• Get quotient and remainder
• Most frequent element of a List
• Convert string to upper case
• Converting string to byte
• Transpose a Matrix
• Element wise addition of 2 lists
• Convert ASCII value to Character and vice versa
• Print all combinations of elements in a List
• Input space separated integers in a list
• Nested for loops via List comprehension
• Find All Indices of an Element in a List
• Convert number of any base to decimal

Sort a dictionary based on multiple conditions

d={'IN':2, 'GE':2, 'AK':3, 'BEG':1}

n_l=sorted(d.items(), key=lambda x: (x[1], len(x[0]),x[0]))

new_d={k:v for k,v in n_l}

# new_d = {'BEG': 1, 'GE': 2, 'IN': 2, 'AK': 3}

Thousand Separator

n=10000000

new_number=f'{n:,}'

# new_number = 10,000,000

Multiply all elements of a list

from numpy import prod
from functools import reduce

l=[2,3,4,4,5,6]

v1=prod(1) # 2880 

v2=reduce((lambda x, y: x * y), l) #2880

Flatten a List

l = [[7,6], [4, 6], [8, 10]]

flattened = [i for j in l for i in j]

# flattened = [7, 6, 4, 6, 8, 10]

Remove duplicate elements from a list

l = [4,4,5,5,6]

new_l=list(set(l))

# new_1 = [4,5,6]

Get quotient and remainder

quotient, remainder = divmod(10,5)

# quotient, remainder = 2,0

Most frequent element of a List

from collections import Counter

l = [1,1,3,4,1,5,6,7,7,2,9]

freq_ele=Counter(l).most_common()[0][0]

# freq_ele = 1

Convert string to upper case

"hi my name is Allwin".upper()

# 'HI MY NAME IS ALLWIN'

Converting string to byte

s="My name is fox and fox is an animal"

s.encode()

# b'My name is fox and fox is an animal'

Transpose a Matrix

matrix = [[1, 2, 3], [3, 4, 6], [5, 6, 7]] 

l=list(list(x) for x in zip(*matrix))

# l = [[1, 3, 5], [2, 4, 6], [3, 6, 7]]

Element wise addition of 2 lists

first = [1,2,3,4,5]

second = [6,7,8,9,10]

final=[x + y for x, y in zip(first, second)]

# final = [7, 9, 11, 13, 15]

Convert ASCII value to Character and vice versa

ord('a') # 97

chr(97) # a

chr(ord('a') + 3) #d

Print all combinations of elements in a List

from itertools import combinations, combinations_with_replacement

nums = [1,2,3,4]

list(combinations(nums, 2)) 
# [(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]

list(combinations_with_replacement(nums, 2)) 
# [(1, 1), (1, 2), (1, 3), (1, 4), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (4, 4)]

list(combinations (nums, 3)) 
# [(1, 2, 3), (1, 2, 4), (1, 3, 4), (2, 3, 4)]

Input space separated integers in a list

l = list(map(int, input().split()))

Read file in python and input it to a list

l = [line.strip() for line in open('abc.txt', 'r')]

Nested for loops via List comprehension

l1 = [1, 2, 3, 4]

l2 = ['a', 'b', 'c']

l = [(x, y) for x in l1 for y in l2]

# [(1, 'a'), (1, 'b'), (1, 'c'), (2, 'a'), (2, 'b'), (2, 'c'), (3, 'a'), (3, 'b'), (3, 'c'), (4, 'a'), (4, 'b'), (4, 'c')]

Find All Indices of an Element in a List

lst = ['a', 'v', 'a', 'c', 'z']

indices = [i for i in range(len(lst)) if lst[i]=='a']

# [0, 2]

Convert number of any base to decimal

int('30', 8) # 24

int('1011', 2) # 11

int('1A', 16) # 26