"""
python正则提取一组数据的第一个字符以及第一个到第三个字符
http://www.bathome.net/thread-38635-1-1.html
 依山居 3:43 2015/12/19

"""
import re
with open("data.txt") as f:
    txt=f.read()
    
rep=re.compile("(\w|~{1})(\w*)")
result1=re.sub(rep,"\\1",txt)
with open("result1.txt","w+") as f:
    f.write(result1)

rep=re.compile("(\w{3})(\w*)")
result2=rep.sub("\\1",txt)
with open("result2.txt","w+") as f:
    f.write(result2)

        
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"""
python切片提取一组数据的第一个字符以及第一个到第三个字符.py
http://www.bathome.net/thread-38635-1-1.html
依山居 1:02 2015/12/17
"""
with open("data.txt") as f:
    txt=[r.rstrip().split() for r in f.readlines()]
    
result1=''
result2=''
for r in txt:
    sstr1=''
    sstr2=''
    for s in r:
        if len(s)>3:
            sstr1+=s[0]+" "
            sstr2+=s[0:3]+" "
        else:
            sstr1+=s
            sstr2+=s
    result1+=sstr1+"\n"
    result2+=sstr2+"\n"

with open("result1.txt","w+") as f:
    f.write(result1)
with open("result2.txt","w+") as f:
    f.write(result2)
复制代码