Syntax error in if condition. Not equals sign highlighted

Question

When I run this I get an invalid syntax error with the "=" part of the "!=" sign highlighted

I don't think it's a syntax problem on that line per say because I tried using a "==" sign and I still got the same error with the second "=" sign being highlighted

def delete(line_number):
    src = "userinfo.txt"
    dest = "tempfile.txt"
    counter = 1
    with open(src, "r") as input:
        with open(dest, "w") as output: 
            for line in input:
                if counter++ != line_number:
                    output.write(line)

Python doesn't have a `++` operator, so the sequence `++ !=` does not make sense. — khelwood, Aug 01 '19 at 08:08
if you need an index, use `for index, line in enumerate(input):`. In addition: `input` is not a good variable name, since it is a built-in function already. — Klaus D., Aug 01 '19 at 08:14
@khelwood really misleading upvoted answer here https://stackoverflow.com/a/1486086/6260170 — Chris_Rands, Aug 01 '19 at 08:14

Shanteshwar Inde · Answer 1 · 2019-08-02T07:17:51.967

Python doesn't support incremental operated like other languages so you need to use + to increment your count.

def delete(line_number):
    src = "userinfo.txt"
    dest = "tempfile.txt"
    counter = 1
    with open(src, "r") as input:
        with open(dest, "w") as output: 
            for line in input:
                counter += 1
                if counter != line_number:
                    output.write(line)

NOTE: counter += 1 is same as counter = counter + 1.

Syntax error in if condition. Not equals sign highlighted

1 Answers1