How to end a program when the line is equal a period-CodePudding

How do I end a program that reads an input line by line and it ends when there's a period (whitespace doesn't matter)

Like for example:

input = "HI
         bye
              ."

the program should end after it reaches the period

I tried doing two things

if line == ".":
    break

if "." in line:
    break

but the first one doesn't take in consideration of whitespace, and the second one doesn't take in consideration of "." in numbers like 2.1

CodePudding user response：

if line.replace(" ", "")[-1] == ".":
    break

.replace(" ", "") removes all white-spaces, and [-1] takes the last character of the string

CodePudding user response：

You need .strip() to remove whitespaces and check the ending character with .endswith():

for line in f:
    if line.strip().endswith("."):
        terminate...

CodePudding user response：

There is a method for strings called endswith, but honestly I would check if the string ends with a '.' through indexing.

if my_str[-1] == '.':
    do_something()

But this also depends on how your string is received. Is it literally from an input? Is it from a file? You may need to add something additional per the circumstance

CodePudding user response：

A few remarks:

you should use triple double quotation marks if you want to literally include a multiline string
I'm assuming you want to go over the input line by line, not just all at once
don't use keywords and the names of builtin and standard (or other already defined) names as names, that's called shadowing

Here's what you might be after:

from io import StringIO

# you need triple double quotes to have a multiline string like this
# also, don't name it `input`, that shadows the `input()` function
text = """HI
       bye
            ."""

for line in StringIO(text):
    if line.strip()[-1] == ".":
        print('found the end')
        break

Note that the StringIO stuff is only there to go over text line by line. The important part, in answering your question, is if line.strip()[-1] == ".":

This solution also works when your text looks like this, for example:

text = """HI
   some words
            bye.   """  # note the space at the end, and the word in front of the period