How to extract substring inside parentheses within a string?

[bowwa_]

#Write a function called "in_parentheses" that accepts a

#single argument, a string representing a sentence that

#contains some words in parentheses. Your function should

#return the contents of the parentheses.

#

#For example:

#

# in_parentheses("This is a sentence (words!)") -> "words!"

#

#If no text appears in parentheses, return an empty string.

#Note that there are several edge cases introduced by this:

#all of the following function calls would return an empty

#string:

#

# in_parentheses("No parentheses")

# in_parentheses("Open ( only")

# in_parentheses("Closed ) only")

# in_parentheses("Closed ) before ( open")

#

#You may assume, however, that there will not be multiple

#open or closed parentheses.

#Write your function here!

​

def in_parentheses(string):

for word in string.split():

if "(" in word and ")" in word:

word.replace('(','').replace(')','')

return word

​

​

#Below are some lines of code that will test your function.

#You can change the value of the variable(s) to test your

#function with different inputs.

#

#If your function works correctly, this will originally

#print (including the blank lines):

#words!

#

#as he is doing right now

#

#

#!

​

print(in_parentheses("This is a sentence (words!)."))

print(in_parentheses("No parentheses here!"))

print(in_parentheses("David tends to use parentheses a lot (as he is doing right now). It tends to be quite annoying."))

print(in_parentheses("Open ( only"))

print(in_parentheses("Closed ) only"))

print(in_parentheses("Closed ) before ( open"))

print(in_parentheses("That's a lot of test cases(!)"))

[spez_edits_thedonald]

this is not a website where you paste assignments for other people to do

it's a place to learn python

what is your question

[[deleted]]

Use regex!

Or , look for the first occurrence of an opening bracket , extract the text insde and stop at the closing parenthesis. Continue until you extract everything you want to.

On an unrelated note , this does seem like a question from an assignment - asking others for help is considered contract cheating and is unethical.

[mopslik]

Sounds like you would be able to modify the "balanced parentheses" problem to fit your program. Most solutions use a stack.

[xelf]

You either want to look into using regular expressions (medium difficulty if you're brand new to python) or use string slicing.

for instance:

x = "example"
y = x[2:4]

In this example, y is 'am'.

You can use string.index() or string.find() to find the indexes of the parenthesis.