命令行中的瑞士军刀：Pythonpy
jopen
11年前
Pythonpy 是命令行的瑞士军刀，个头虽小，但功能强大。
Installation
sudo pip install pythonpy # restart your shell for tab completion to take effect
py 'expression' ≅ python -c 'print(expression)'
Float Arithmetic
$ py '3 * 1.5' 4.5
Access imports directly
$ py 'math.exp(1)' 2.71828182846 $ py 'random.random()' 0.103173957713 $ py 'datetime.datetime.now?' Help on built-in function now: now(...) [tz] -> new datetime with tz's local day and time.
Lists are printed row by row
$ py 'range(3)' 0 1 2 $ py '[range(3)]' [0, 1, 2]
py -x 'foo(x)' will apply foo to each line of input
Multiply each line of input by 7.
$ py 'range(3)' | py -x 'int(x)*7' 0 7 14
Append ".txt" to each line of input
$ py 'range(3)' | py -x 'x + ".txt"' 1.txt 2.txt 3.txt
Append ".txt" to every file in the directory
$ ls | py -x '"mv %s %s.txt" % (x,x)' | sh
Get only even numbers
$ py 'range(8)' | py -x 'x if int(x)%2 == 0 else None' 0 2 4 6
py -fx 'predicate(x)' filters rows satisfying a condition
Get only odd numbers
$ py 'range(8)' | py -fx 'int(x)%2 == 1' 1 3 5 7
Get words starting with "and"
$ cat /usr/share/dict/words | py -fx 're.match(r"and", x)' | head -5 and andante andante's andantes andiron
Get verbs starting with ba
$ cat /usr/share/dict/words | py -fx 're.match(r"ba.*ing$", x)' | head -5 baaing babbling babying babysitting backbiting
Get long palindromes
$ cat /usr/share/dict/words | py -fx 'x==x[::-1] and len(x) >= 5' | head -5 civic deified kayak level ma'am
py -l will set l = list(sys.stdin)
Reverse the input
$ py 'range(3)' | py -l 'l[::-1]' 2 1 0
Sum the input
$ py 'range(3)' | py -l 'sum(int(x) for x in l)' 3
Count the lines of input
$ py 'range(17)' | py -l 'len(l)' 17
Count words beginning with each letter
$ cat /usr/share/dict/words | py -x 'x[0].lower()' | py -l 'Counter(l).most_common(5)' ('s', 11327) ('c', 9521) ('p', 7659) ('b', 6068) ('m', 5922)