Python one-liners
This blog post contains some of the python one-liners which I have gathered from various sources. The link to the repository is given below. If you are interested you can also add your own one-liners if I have missed any.
https://github.com/Allwin12/python-one-liners
anagram
from collections import Counter
s1 = 'below'
s2 = 'elbow'
print('anagram') if Counter(s1) == Counter(s2) else print('not an anagram')
binary to decimal
decimal = int('1010', 2)
print(decimal) #10
convert string to lower case
"Hi my name is Allwin".lower() # 'hi my name is allwin' "Hi my name is Allwin".casefold() # 'hi my name is allwin'
convert string to upper case
"hi my name is Allwin".upper() # 'HI MY NAME IS ALLWIN'
convert string to bytes
"convert string to bytes using encode method".encode() # b'convert string to bytes using encode method'
copy files
import shutil; shutil.copyfile('source.txt', 'dest.txt')
quick sort
qsort = lambda l : l if len(l)<=1 else qsort([x for x in l[1:] if x < l[0]]) + [l[0]] + qsort([x for x in l[1:] if x >= l[0]])
sum of n consecutive numbers
sum(range(0, n+1)
swap two values
a,b = b,a
fibonacci series
lambda x: x if x<=1 else fib(x-1) + fib(x-2)
flat list out of list of lists
[item for sublist in main_list for item in sublist]
starting a http server
python3 -m http.server 8000
reverse a list
numbers[::-1]
factorial of a number
import math; fact_5 = math.factorial(5)
floor division result
print(5//2) # 2
for and if
new_li = [number for number in [1, 2, 3, 4] if number % 2 == 0] # [2, 4]
longest string in a list
# words = ['This', 'is', 'a', 'list', 'of', 'words'] max(words, key=len) # 'words'
list comprehension
li = [num for num in range(0,100)] # this will create a list of numbers from 0 to 99
set comprehension
num_set = { num for num in range(0,100)}
# this will create a set of numbers from 0 to 99
dictionary comprehension
dict_numbers = {x:x*x for x in range(0,5) }
if else
print("even") if 4%2==0 else print("odd")
infinite while loop
while 1:0
check data type
isinstance(2, int)
isinstance("allwin", str)
isinstance([3,4,1997], list)
while loop
a=5 while a > 0: a = a - 1; print(a)
write to a file using print
print("Hello, World!", file=open('file.txt', 'w'))
count occurence of a character in a string
print("umbrella".count('l'))
merge two lists
list1.extend(list2) # contents of list 2 will be added to the list1
merge two dictionaries
dict1.update(dict2) # contents of dictionary 2 will be added to the dictionary 1
merge two sets
set1.update(set2) # contents of set2 will be copied to the set1
get timestamp
import time; print(time.time())
most frequent element in a list
numbers = [9, 4, 5, 4, 4, 5, 9, 5, 4] most_frequent_element = max(set(test_list), key=test_list.count) # 4
from collections import Counter numbers = [9, 4, 5, 4, 4, 5, 9, 5, 4] print(list(Counter(numbers).most_common())) # [(4, 4), (5, 3), (9, 2)]
nested list comprehension
numbers = [[num] for num in range(10)] # [[0], [1], [2], [3], [4], [5], [6], [7], [8], [9]]
octal to decimal
print(int('30', 8))
# 24
repeat values in a list for n time
import itertools; print(list(itertools.repeat(10,5))) # [10, 10, 10, 10, 10] will be printed
generate a random number of n digits
from random import randint; print(''.join(["{}".format(randint(0, 9)) for num in range(0, n)]))
# This will print 1038496714 given the value of n=10
convert key value pair to dictionary
dict(name='allwin', age=23)
get quotient and remainder
quotient, remainder = divmod(4,5)
python zen
import this
remove duplicate elements from a list
list(set([4, 4, 5, 5, 6]))
sort list in ascending order
sorted([5, 2, 9, 1])
sort list in descending order
sorted([5, 2, 9, 1], reverse=True)
get a string of small case alphabets
import string; print(string.ascii_lowercase) # abcdefghijklmnopqrstuvwxyz
get a string of upper case alphabets
import string; print(string.ascii_uppercase) # ABCDEFGHIJKLMNOPQRSTUVWXYZ
get a string of digits from 0 to 9
import string; print(string.digits) # 0123456789
get individual digits from a number
digits = [int(digit) for digit in str(12345)]
hexadecimal to decimal
print(int('da9', 16))
# 3497
hypotenuse
import math; math.hypot(8, 6)
human readable datetime
import time; print(time.ctime()) # Thu Aug 13 20:16:23 2020
convert decimal to binary
bin(24)
convert decimal to octal
oct(24)
convert decimal to hexadecimal
hex(24)
convert a list of strings to integers
list(map(int, ['1', '2', '3'])) # [1, 2, 3]
combine strings from a list
" ".join(["hello", "world"]) # "hello world"
combine two lists to dictionary
dict(zip([1,2,3,4], ['a','b','c','d']))
{1: 'a', 2: 'b', 3: 'c', 4: 'd'}
common element between two lists
list1 = [1, 2, 4, 5]
list2 = [6, 8, 4, 2]
print(set(list1) & set(list2))
print(set(list1).intersection(set(list2)))
# {2, 4}
get even numbers from a list
list(filter(lambda x: x%2 == 0, [1, 2, 3, 4, 5, 6] )) # [2, 4, 6]
input a list of tuples
list(tuple(map(int, input().split())) for r in range(int(input('enter the no of rows:'))))
# enter the no of rows:
# 3
# 1 2
# 3 4
# 5 6
# [(1, 2), (3, 4), (5, 6)]
transpose matrix
list(list(x) for x in zip(*old_list)) # old_list = [[1, 2, 3], [3, 4, 6], [5, 6, 7]] # [[1, 3, 5], [2, 4, 6], [3, 6, 7]]
remove numbers from string
''.join(list(filter(lambda x: x.isalpha(), 'abc123def4fg56vcg2'))) # abcdeffgvcg
replace words in a sentence
string = "He is a good boy"
string.replace('good', 'bad')
# returns 'he is a bad boy'
rotate a list
# li = [1,2,3,4,5] # right to left li[n:] + li[:n] # n is the no of rotations li[2:] + li[:2] [3, 4, 5, 1, 2] # left to right li[-n:] + li[:-n] li[-1:] + li[:-1] [5, 1, 2, 3, 4]
sort dictionary with values
# x = {1: 2, 3: 4, 4: 3, 2: 1, 0: 0}
{k: v for k, v in sorted(x.items(), key=lambda item: item[1])}
# {0: 0, 2: 1, 1: 2, 4: 3, 3: 4}
sort dictionary with key
# {'one': 1, 'four': 4, 'eight': 8}
{key:d[key] for key in sorted(d.keys())}
# {'eight': 8, 'four': 4, 'one': 1}
substring in a string
'sent' in 'sentence' # returns True
unpacking elements
a, *b, c = [1, 2, 3, 4, 5] print(a) # 1 print(b) # [2, 3, 4] print(c) # 5