用PYTHON进行字符串提取的两种方法

一、提取某两个标记之间的文本内容（多行）

有文本内容如下：

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fdsjhgjhg

fdshkjhk

Start

Good Morning

Hello World

End

dashjkhjk

dsfjkhk

我需要用Python实现——获取”Start”和”End”之间的内容并写入结果文件。

解决方法1：

with open('/path/to/input') as infile, open('/path/to/output', 'w') as outfile:

    copy = False
    for line in infile:
        if line.strip() == "Start":
            copy = True
        elif line.strip() == "End":
            copy = False
        elif copy:
            outfile.write(line)

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withopen('/path/to/input')asinfile,open('/path/to/output','w')asoutfile:

    copy=False

    forlineininfile:

        ifline.strip()=="Start":

            copy=True

        elifline.strip()=="End":

            copy=False

        elifcopy:

            outfile.write(line)

解决方法2：

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withopen('input.txt')asmyfile:

    content=myfile.read()

 

text=re.search(r'Start\n.*?End',content,re.DOTALL).group()

 

withopen("output.txt","w")asmyfile2:

    myfile2.write(text)

解决方法3：

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importitertools

withopen('input.txt','r')asf,open('output.txt','w')asfout:

    whileTrue:

        it=itertools.dropwhile(lambdaline:line.strip()!='Start',f)

        ifnext(it,None)isNone:break

        fout.writelines(itertools.takewhile(lambdaline:line.strip()!='End',it))

参考链接：

http://stackoverflow.com/questions/18865058/extract-values-between-two-strings-in-a-text-file-using-python

二、提取某两个字符串之间的内容（单行）

解决方法（字符串切片）：

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'''

get content between str1 and str2 in str

'''

defgetBetween(str,str1,str2):

    strOutput=str[str.find(str1)+len(str1):str.find(str2)]

    returnstrOutput

参考链接：

https://github.com/bfishadow/SBB

三、其它的实现方式

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sed-n'/Start/,/End/p'input.txt|grep-Ev'(Start|End)'

 

sed-e'1,/Start/d'-e'/End/,$d'input.txt

 

awk/Start/,/End/input.txt|grep-Ev'(Start|End)'

 

awk'/Start/{flag=1;next} /End/{flag=0} flag{ print }'input.txt

 

awk'/End/{flag=0} flag; /Start/{flag=1}'input.txt

 

perl-lne'print if((/Start/../End/) && !(/Start/||/End/))'input.txt

搜索关键字：

• awk print line between

参考链接：

• http://www.unix.com/shell-programming-and-scripting/48676-how-print-only-lines-between-two-strings-using-awk.html
• https://nixtip.wordpress.com/2010/10/12/print-lines-between-two-patterns-the-awk-way/
• http://www.shellhacks.com/en/Using-SED-and-AWK-to-Print-Lines-Between-Two-Patterns
• http://stackoverflow.com/questions/17988756/how-to-select-lines-between-two-marker-patterns-which-may-occur-multiple-times-w

=EOF=

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