# Python Programming/Command-line one-liners

Python can run one-liners from an operating system command line using
option -c:

-   python -c \"print(3.0/2)\"
    -   Calculates and outputs the result.
-   python -c \"import math;print(math.sin(1))\"
    -   Imports a module required and outputs sine value.
-   python -c \"for i in range(1,11):print(i)\"
    -   Uses a loop to output numbers from 1 to 10.
-   python -c \"for i in range(1,11):for j in range(1,11): print(i,j)\"
    -   Does not work; two loops in a line are an invalid syntax.
-   python -c \"for i, j in ((i,j) for i in range (1,11) for j in
    range(1,11)): print(i, j)\"
    -   Outputs pairs using two analogues of loop within a
        comprehension.
-   echo hey \| python -c \"import sys,re;\[sys.stdout.write(line) for
    line in sys.stdin if re.search(\'he.\', line)\]\"
    -   Acts as grep: outputs each line of the input containing a
        substring matching a regular expression. Not a Python one-liner
        strength.
-   echo hallo \| python -c \"import
    sys,re;\[sys.stdout.write(re.sub(\'h\[au\]llo\', \'hello\', line))
    for line in sys.stdin\]\"
    -   Acts as sed: for each line of the input, performs a regex
        replacement and outputs the results. Again, not a Python
        one-liner strength.
-   python -m calendar
    -   Outputs a year\'s calendar using calendar module.
-   python -c \"import playsound as
    p;p.playsound(r\'C:\\WINDOWS\\Media\\notify.wav\')\"
    -   On Windows, plays notification sound. Requires installation of
        playsound module. The module works across platforms; what is
        Windows specific above is the file path.

## External links

-   Powerful Python
    One-Liners,
    wiki.python.org

