如何从文本文件中删除特定行？

Question

file = open(userid, "r+") 
#userid is in the form
# A
# B
# C
# etc...
removeRead = file.readlines()
del removeRead[int(index)]
file.write(str(removeRead))

This is what I've tried so far. Ive looked at other questions asking this and one of the suggestions was to 'simply iterate over the whole file and write all the lines except the one you want to remove` with their suggestion being

with open('fordel.txt') as f, open('out.txt', 'w') as fo:
    for linenum, line in enumerate(f, start=1):
        if linenum != badline:
            fo.write(line)
    # obviously not to my code

Is this really the simplest solution (ie does python really not have an inbuilt solution for this?), and how exactly does it work so I can implement it into my code?

Answer 1

I am not sure if you require the enumerate() as that is to keep track/count of the number of lines, you could use if you really knew the line at which you want to remove some specific line, but this a maybe simpler variation, give it a shot:

  with open("originalfile.txt", "r") as currentfile:
    with open("finalfile.txt", "w") as endfile: 
      for line in currentfile:
        if line.strip("\n") != "the line you want to delete":
           endfile.write(line)