This document provides examples of concise Python code snippets called "1-liners" that perform various tasks in a single line. Some examples include: using a list comprehension to square each element in a range, using map and filter to sanitize a string by keeping only digit characters, sorting a list while preserving the original order of equal elements using a key function, and using zip and enumerate to pair elements from two lists. The document encourages writing functional style code in Python using features like lambda functions and list comprehensions to accomplish tasks in a single line when possible.

1. Python 1-Liners
@neizod

2. <http://about.me/neizod>

3. 1-Liners?

4. 1st Impression
C Python
int i = 7; i = 7
int j = 11; j = 11
int temp; i, j = j, i
temp = i;
i = j;
j = temp;

5. 1-Liner = 1 Line of Code
JavaScript Array Summation
a = [1, 1, 2, 3, 5, 8, 13];
for(var s=i=0;(b=a[i++])?s+=b:alert(s););

6. But NOT This Kind of 1 Line!
for(int i = 0; i < 100; i++) { printf
("hellon"); if(i == 42) break; }
Cause this is actually:
for(int i = 0; i < 100; i++) {
printf("hellon");
if(i == 42)
break;
}

7. Let's Do It

8. Looping w/ List Comprehension
[x**2 for x in range(10)]
output:
[0, 1, 4, 9, 16, 25, 3, 49, 64, 81]

9. Sanitize w/ Map & Filter
[int(c) for c in '4f3c87' if c.isdigit()]
output:
[4, 3, 8, 7]

10. Use Shorthand If-Else
-x if x < 0 else x
r = [5, -2, 31, 13, -17]
[-x if x < 0 else x for x in r]
output:
[5, 2, 31, 13, 17]

11. Go For Functional
OOP doesn't return value!
a = [42, 8, 16, 15, 4, 23]
a.sort()
a.reverse()
Use this instead:
sorted([42, 8, 16, 15, 4, 23])[::-1]

12. Join Those String
' '.join(['hello', 'world'])
' < '.join(sorted('powerful'))
output:
'e < f < l < o < p < r < u < w'

13. Zip and Enumerate
[a+b for a, b in zip('hello', 'world')]
output:
['hw', 'eo', 'lr', 'll', 'od']

14. Hide Input w/ String Formatting
'{0} <3 {2}'.format('i', input(), 'u')
output:
'i <3 u'

15. Use Lambda
sorted([2, 1, 8, -7], key=lambda x: x**2)
output:
[1, 2, -7, 8]

16. Go For Combinator
(lambda i: (lambda f, a: f(f, a))(
lambda r, n:
n * (r(r, n-1) if n > 1 else 1),
i))(10)
output:
3628800

17. Question?

18. Reference
● Python 1-Liners - gist
● Powerful Python One-Liners - wiki.python
● Obfuscated one-liners in Python - effbot
● Stupid lambda tricks - p-nand-q