如何分离输入的一部分并将其转换为变量？

Question

I'm working on a simple program and I was wondering how can I separate a part of the input and turn that separated part into a variable.

For example: START {chrome.exe} .

Basically I want to take that string in between those curly brackets and turn it into a variable.

Thanks,

Answer 1

For this kind of operation, it is a good idea to use regular expressions . Python has a builtin module for using regexes, called re . You can use its findall function to find all the strings which match a certain pattern, and then simply get the first item in the resulting list (which will only have one item anyway).

---

Here is what the code would look like:

import re

inp = input()
var = re.findall(r"{(.*?)}", inp)

print(var)

Given an input of:

START {chrome.exe}

This outputs:

chrome.exe

---

Here is an explanation of how the regex works:

• The { and } characters match the literal characters { and }
• The ( and ) characters are special characters which group together tokens
• The . character is a special character which matches any character except newlines
• The * character is a special character which means that the last token can match any number of itself (not just 1). This means that the . will now match a run of multiple non-newline characters, not just one character
• The ? character is a special character which alters the meaning of the preceding * . Now, instead of matching as many characters as possible ("greedy"), which would cause the .* to continue after the } and match the whole rest of the string, the .*? matches as few characters as possible ("lazy"), so it only matches up to the next } character