strings.md

Definition

A string is a series of letters, numbers, symbols enclosed in single quote (‘) or double quote (“).

Creation

Let's try some ways to create strings!

greeting = "WWC is awesome!"
title = 'StringPaMore'
hash_symbol = "#"
hashtag = hash_symbol + title
rating = str(5)
print("{} {} stars for them! {}".format(greeting, rating, hashtag))
# print(f"{greeting} {rating} stars for them! {hashtag}")  # For versions Python3.6

String methods

Let's try some string methods!

movie_title = "My ex and whys"
print(len(movie_title))

comment = "HINDI AKO GALIT!"
print(comment.lower())
print(comment.islower())

shout = "darna!"
print(shout.upper())

Accessing string characters

Given a person's firstname and lastname, can we get the name initial?

!> Experiment on how to print the name initials with the code below!

firstname = "Fred"
lastname = "Jowson"

# TRY TO FIGURE OUT HOW TO PRINT OUT THE NAME INITIALS

We can access string characters through this syntax: your_string[index]

Each character in a string is represented by an index number starting from 0

Here's an image to guide you with indexing.

Let's experiment more!

my_strings

Immutable

Now, since we can access characters from a string, let's try to change its value! Is the code below successful?

mispelled_word = "beleive"
# This should raise an error
mispelled_word[3] = "i"
mispelled_word[4] = "e"

# What we can do is to re-assign the variable to a new string
mispelled_word = "believe"

!> Strings are immutable, meaning we cannot change it's value after creation. Hence, the code above resulted to an error!

Challenge

This summer, Aling Nena’s Sari-sari store wants to implement a reward system where customers can redeem a reward by texting the following:

<Reward number 1-9> <Customer’s name> <Gender f or m>

>> Please enter text: 1 nicole i. tibay f

The system will then reply the following:

Hi <Customer’s name Capitalized>! You have successfully redeem reward #<reward number> - <reward>! Thank you for choosing Aling Nena’s Sari-sari store.

>> Hi Nicole I. Tibay! You have successfully redeem reward #1 - Coke sakto!
Thank your for choosing Aling Nena’s Sari-sari store”

Let’s assume that customers will always comply with the text format and give 1-9 number.

!> Please use below template

filename

challenge_partial

Put your thinking cap on!

• What is the reasoning behind PEP8's break before binary operations?
• What does the str() function do?
• Do you find any difference in using len(<your string>) and <your string>.lower()? Can you explain?
• Explain string immutability.