Python One Liners

In Python, a "one-liner" is a concise and frequently ingenious solution to a problem that can be stated in only one line of code. For readability and maintainability in bigger codebases, they are not always advised, despite their sometimes-elegant and potent nature. They are, nevertheless, frequently employed in scripting, where conciseness is valued. Here are a few sample lines of code for one-liner solutions.

• Multiple variable assignments

name, age, occupation = "keisha", 30, "cook"
print(name, age, occupation)
# keisha 30 cook

• HTTP server

python -m http.server

• Swap variables

a = "a"
b = "b"
a, b = b, a
print(a, b)
# b a

• Ternary operator

yob = 1997
print("hey kid(gen alpha)" if yob >= 2013 else "wassup gen z" if yob >= 1995 else"hello millennials" if yob >= 1980 else "hey gen x" if yob >= 1965 else "hello baby boomer")
# wassup gen z

• Variable unpacking

users = ['kalama', 'kairetu','munga','mwanaisha']
print(*users)
#kalama kairetu munga mwanaisha

user1, user2 , *other_users= users
print(other_users)
#['munga', 'mwanaisha']

• Reverse a list

z = [10,20,30,40]
print(z[::-1])
#[40, 30, 20, 10]

• Sort a list

numbers = [1000000, -500000, 999999999, -1000000000, 123456789]
print(sorted(numbers))
# [-1000000000, -500000, 1000000, 123456789, 999999999]

• Sort a list - reversed

numbers = [1000000, -500000, 999999999, -1000000000, 123456789]
print(sorted(numbers, reverse=True))
#[999999999, 123456789, 1000000, -500000, -1000000000]

• Filter from a list

numbers = [1,2,3,4,5,6,7,8,9,10]
odd = list(filter(lambda x: x%2!=0, numbers))
print(odd)
#[1, 3, 5, 7, 9]

• List comprehension

names = ['lizzy','bruce','wafula']
print([name.title() for name in names])
#['Lizzy', 'Bruce', 'Wafula']

• Remove duplicates from a list

num = [5, 2, 8, 3, 5, 2, 1, 8, 9, 4, 1]
print(list(set(num)))
# [1, 2, 3, 4, 5, 8, 9]

• Combine two lists to a dictionary

letters = ["a", "b", "c", "d"]
num = [1,2,3,4]
print(dict(zip(letters, num)))
# {'a': 1, 'b': 2, 'c': 3, 'd': 4}

• Unpacking using * operator and zip

pair = [('jack', 50),('inaam', 80), ( 'Anna ', 70), ('John', 35)]
names, marks = zip(*pair)
print(names)
print(marks)
#('jack', 'inaam', 'Anna ', 'John')
#(50, 80, 70, 35)

• Type conversion of items in an iterable using map function

strings = ("1","2","3","4","5","6","7","8")
print(tuple(map(int, strings)))
# (1, 2, 3, 4, 5, 6, 7, 8)

• Alternative value for input statements

username = input('Name: ') or 'N/A'

#using ternary operator

name_input = input('Name: ')
username = name_input if name_input else 'N/A'

• Creating a shadow copy of a list

mylist = [1,2,3,4,5]
copy_list = mylist[:]