读取文件导致的错误

Question

I am facing a rather elusive bug which seems to be caused by reading from a file. I have simplified my program to demonstrate the issue:

consider this program that works fine:

import re

sourceString="Yesterday I had a pizza for lunch it was tasty\n";
sourceString+="today I am thinking about grabbing a burger and tomorrow it\n"; 
sourceString+="will probably be some fish if I am lucky\n\n\n";
sourceString+="see you later!"

jj=["pizza","steak","fish"]

for keyword in jj:
    regexPattern= keyword+".*";
    patternObject=re.compile(regexPattern,re.MULTILINE);
    match=patternObject.search(sourceString);
    if match:
        print("Match found for "+keyword)
        print(match.group()+"\n")
    else:
        print("warning: no match found for :"+ keyword+"\n")

I am using a very straightforward regex pattern but I am getting the gist of the regex from my array jj

the script works as expected (matches patterns containing "pizza" and "fish" but does not match "steak")

now In my actual program I am trying to read these keywords from a file (I don't want to hardcode in the source)

so far I have this:

import re

sourceString="Yesterday I had a pizza for lunch it was tasty\n";
sourceString+="today I am thinking about grabbing a burger and tomorrow it\n"; 
sourceString+="will probably be some fish if I am lucky\n\n\n";
sourceString+="see you later!"

with open('keyWords.txt','r') as f: 
    for keyword in f:
        regexPattern= keyword+".*";
        patternObject=re.compile(regexPattern,re.MULTILINE);
        match=patternObject.search(sourceString);
        if match:
            print("Match found for "+keyword)
            print(match.group())
        else:
            print("warning: no match found for :"+ keyword)

where keyWords.txt will contain the following:

pizza
steak
fish

but this breaks the code because somehow only the LAST keyword in the file will successfully match (if a match exists).

What gives?

Answer 1

with open('keyWords.txt','r') as f: 
    for keyword in f:
        regexPattern = keyword.strip() + ".*";

Use strip() to remove any newline characters from keyword . If you know for certain that there won't be any leading whitespace, rstrip() is sufficient.