搜索文本文件并在Python中打印相关的行？

Question

如何在文本文件中搜索关键短语或关键字,然后打印关键短语或关键字所在的行？

Answer 1

searchfile = open("file.txt", "r")
for line in searchfile:
    if "searchphrase" in line: print line
searchfile.close()

打印多行(以简单的方式)

f = open("file.txt", "r")
searchlines = f.readlines()
f.close()
for i, line in enumerate(searchlines):
    if "searchphrase" in line: 
        for l in searchlines[i:i+3]: print l,
        print

逗号print l,可以防止额外的空格出现在输出中; 尾随打印语句划分不同行的结果.

或者更好(从Mark Ransom手中抢回):

with open("file.txt", "r") as f:
    searchlines = f.readlines()
for i, line in enumerate(searchlines):
    if "searchphrase" in line: 
        for l in searchlines[i:i+3]: print l,
        print

Answer 2

with open('file.txt', 'r') as searchfile:
    for line in searchfile:
        if 'searchphrase' in line:
            print line

向我肆无忌惮地复制的发送者道歉.