Why is a new line being created when concatenating strings

Question

I'm trying to open a file, and edit a specific line. When I concatenate a character onto one of the lines, it works, but inserts a new line. However I don't want a new line. Here is the code:

def moveCurlyInline(line, i):
    with open('test.js', 'r') as inputFile:
        data = inputFile.readlines()
        print(data[0])
        print(data[0] + ' {')

The print outputs:

function hello()

then:

function hello()
 {

I need the curly bracket to be on the same line as the function hello. Any idea what's wrong with my code?

Because every string in your list ends with a newline. Did you try printing the `repr`? — juanpa.arrivillaga, Jan 03 '19 at 18:43
Take a look at [this answer](https://stackoverflow.com/a/12330535/532978). Basically, when you use `inputFile.readlines()` the output has newline characters on the end of every line. — JCOC611, Jan 03 '19 at 18:43
Possible duplicate of [Trouble concatenating two strings](https://stackoverflow.com/questions/7084937/trouble-concatenating-two-strings) — Jongware, Jan 03 '19 at 18:44

score 1 · Accepted Answer · answered Jan 03 '19 at 18:44

1

f.readline() reads a line from the file, including the newline at the end of the line.

Try stripping the extra newline:

data = [line.rstrip("\n") for line in inputFile]

answered Jan 03 '19 at 18:44

iBug

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Thanks, this helped a lot! – dwib Jan 03 '19 at 18:47

mad_ · Answer 2 · 2019-01-03T18:53:46.747

1

You can strip new line character by

inputFile.read().striplines()

edited Jan 03 '19 at 18:53

answered Jan 03 '19 at 18:45

mad_

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Why is a new line being created when concatenating strings

2 Answers2