删除文件中包含python中某个单词的行

Question

我的输入文件是这样的

car
dog
Rock

我试图编辑的输出文件如下所示。我的全部目标是删除所有包含单词 car 的行

cat car
sky rat
car cloud

这是我的初始代码，这里的问题是只有当它在这种情况下实际上只有“汽车”这个词时才会删除该行

from __future__ import print_function
import linecache
import fileinput

must_delete = linecache.getline('Test.txt', 1)

for line in fileinput.input('output.txt', inplace=True):
    if line != must_delete:
        print(line, end='')

Answer 1

from __future__ import print_function
import re
import linecache
import fileinput

must_delete = "car" # linecache.getline('Test.txt', 1)

text = '''
cat car g
sky rat
car cloud
scary thing
''' 

with open("cleaned_file.txt","w") as clean:
    for line in text.splitlines() :          # fileinput.input('output.txt', inplace=True):
        if  re.search(r"(\b"+must_delete+r"\b)", line, flags=re.IGNORECASE):
            print ("deleting line:"+ line)
        else:
            print ("this line has to be kept in the output: " + line)
            clean.write(line+"\n")

# cleaned_file.txt has all the needed lines

输出：

this line has to be kept in the output: 
deleting line:cat car g
this line has to be kept in the output: sky rat
deleting line:car cloud
this line has to be kept in the output: scary thing

我使用了一个正则表达式，其中包含您要删除的单词和两个单词边界，因此 car 必须是一个完整的单词。如果未找到正则表达式，re.search() 返回 None。

正如 cmets 中所指出的，“可怕”也包含“汽车”——这就是简单的 if "car" in "scary": 不足以清除包含“汽车”但不是“汽车”的单词的原因。