Question

如何在文本文件中搜索关键词或关键词，然后打印关键词或关键词所在的行？

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

print l,中的逗号可防止额外空格出现在输出中;尾随打印语句划分不同行的结果。

或者更好（从Mark Ransom那里偷回来）：

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

向我公然抄袭的senderle道歉。

Answer 3

注意“i + 3”超出范围索引的可能性。你可以这样做：

with open("file.txt", "r") as f:
    searchlines = f.readlines()
j=len(searchlines)-1
for i, line in enumerate(searchlines):
    if "searchphrase" in line: 
        k=min(i+3,j)
        for l in searchlines[i:k]: print l,
        print

编辑：也许没必要。我刚刚测试了一些例子。如果y超出范围，x [y]将给出错误，但x [y：z]似乎不会给y和z的超出范围值带来错误。

搜索文本文件并在Python中打印相关的行？

3 个答案: