Text values are strings (str), and you’ll shape them constantly — greetings, labels,
messages. Start by joining strings together with +, which for text means “stick these
end to end”:
greeting = "Hello" + " " + "World"
print(greeting)Hello World
That works with variables too:
first = "Ada"
last = "Lovelace"
print(first + " " + last)Ada Lovelace
Joining with + gets clumsy fast — and it breaks the moment you try to mix in a number
(you saw that TypeError earlier). The modern, readable way is an f-string: put f
before the quotes, then drop any variable inside { }:
name = "Ada"
age = 36
print(f"{name} is {age} years old")Ada is 36 years old
Notice age is a number, and the f-string inserted it with no fuss — no converting
required. That’s why f-strings are the tool you’ll reach for again and again.
len() tells you how many characters a string has:
print(len("hello"))5
And you can combine tools — an f-string with len() inside:
word = "Python"
print(f"{word} has {len(word)} letters")Python has 6 letters
Every character has a position, called its index. The catch that trips up every
beginner: indexing starts at 0, not 1. So the first character is at index 0:
word = "Python"
print(word[0])P
A negative index counts back from the end, so -1 is the last character:
word = "Python"
print(word[-1])n
Trying to join text and a number with + fails — Python won’t guess what you mean:
print("Score: " + 100)TypeError
The clean fix is an f-string, which handles the number for you:
score = 100
print(f"Score: {score}")Score: 100
"abc"[5]) raises IndexError. For a 3-character string the
valid indexes are 0, 1, 2 (and -1, -2, -3).len("a b") is 3, and a single space " " has length 1.What happens when you run print("Score: " + 100)?
Python raises a TypeError — you can't add text and a number — "Score: " is text and 100 is a number, so + raises TypeError. Use an f-string, f"Score: {100}", or convert with str(100).
In the string "Python", what is at index 0?
'P' — indexing starts at 0 — Python indexes from 0, so "Python"[0] is 'P', [1] is 'y', and so on.
Which line correctly prints: Ada is 36 years old (with name = "Ada", age = 36)?
print(f"{name} is {age} years old") — The f-string inserts both values automatically. The second line fails (can't + a number to text); the third has no f, so the braces stay as literal text.
What is len("a b") (note the space)?
3 — the space is a character too — len() counts every character, and a space is a real character. "a b" is 'a', ' ', 'b' — length 3.
Create a variable city set to "Paris", then use an f-string to print exactly: I love Paris
Start the string with f and put {city} where the name should go.
city = "Paris"
print(f"I love {city}")Given word = "Python", print its length on the first line and its last character on the second line.
len(word) gives the length; word[-1] gives the last character.
word = "Python"
print(len(word))
print(word[-1])