String Manipulation & Indexing

Strings are fundamental for working with text in Python. Understanding indexing and slicing is crucial for text processing and manipulation.

What are Strings?

message = "Python"
print(len(message))  # → 6
→
6
Strings are immutable sequences of Unicode characters. They can be:
  • Indexed: message[0] → 'P'
  • Sliced: message[2:5] → 'tho'
  • Concatenated: "Py" + "thon"

Indexing Characters

word = "Elephant"
print(word[0])   # → E
print(word[3])   # → p
→
E
p

In this example:

  • Indexes start at 0 for first character
  • word[3] accesses 4th character
  • Indexes beyond length cause IndexError

Reverse Access

city = "Paris"
print(city[-1])  # → s
print(city[-3])  # → i
→
s
i

Negative indexes count from the end:

  • -1 → Last character
  • -2 → Second last

String Slicing

phrase = "Hello World"
print(phrase[0:5])   # → Hello
print(phrase[6:11])  # → World
→
Hello
World

Slice syntax: [start:end:step]
End index is exclusive. Omit start/end for defaults.

Practical Use: Usernames

email = "user.name@domain.com"
username = email[:email.index("@")]
print(f"Username: {username}")
→
Username: user.name

Your Task: Character Extraction

Given text = "hello":

  1. Store first character in first
  2. Store last character in last
  3. Use indexing (both positive and negative)

Final output should be: First: h, Last: o

Section 1/6What are Strings?

What are Strings?

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String Manipulation & Indexing

Strings are fundamental for working with text in Python. Understanding indexing and slicing is crucial for text processing and manipulation.

What are Strings?

message = "Python"
print(len(message))  # → 6
→
6
Strings are immutable sequences of Unicode characters. They can be:
  • Indexed: message[0] → 'P'
  • Sliced: message[2:5] → 'tho'
  • Concatenated: "Py" + "thon"

Output:

Click "Check" to run your code.