cat，grep和cut-翻译成python

cat，grep和cut-翻译成python

您需要更好地了解python语言及其标准库才能翻译表达式

cat“ $ filename”：读取文件

cat"$filename"

并将内容转储到stdout

|

：管道将上

stdout

一条命令重定向，并将其馈送到

stdin

下一条命令的

grep“ something”：搜索正则表达式

something

纯文本数据文件（如果已指定）或在stdin中，并返回匹配的行。

cut -d’“’-f2：使用特定的定界符分割字符串，并从结果列表中索引/拼接特定字段

相当于Python

cat "$filename"  | with open("$filename",'r') as fin:        | Read the file Sequentially      |     for line in fin:|   -----------------------------------------------------------------------------------grep 'something' | import re| The python version returns      | line = re.findall(r'something', line)[0]  | a list of matches. We are only      |          | interested in the zero group-----------------------------------------------------------------------------------cut -d'"' -f2    | line = line.split('"')[1]      | Splits the string and selects      |          | the second field (which is      |          | index 1 in python)

结合

import rewith open("filename") as origin_file:    for line in origin_file:        line = re.findall(r'something', line)        if line:line = line[0].split('"')[1]        print line