Python allows you to access characters from the end of a string using negative indexing.

Instead of counting from the beginning, negative indexing starts counting from the end of the string.

The last character has an index of -1, the second last character has an index of -2, the third last character has an index of -3, and so on.

Negative indexing is useful when you need to access characters near the end of a string without knowing its exact length.

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Syntax #

string_name[negative_index]

Components #

Component	Description
string_name	The string variable.
[ ]	Square brackets used for indexing.
negative_index	Position counted from the end of the string.

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Example 1: Accessing the Last Character #

main.py

language = "Python"

print(language[-1])

Output #

n

Explanation #

• Negative indexing starts from the end.
• Index -1 always refers to the last character.
• Therefore, language[-1] returns n.

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Example 2: Accessing the Second Last Character #

main.py

language = "Python"

print(language[-2])

Output #

o

Explanation #

• Index -2 refers to the second last character.
• The second last character in "Python" is o.

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Example 3: Accessing Multiple Characters #

main.py

language = "Python"

print(language[-1])
print(language[-3])
print(language[-6])

Output #

n
h
P

Explanation #

• -1 returns the last character n.
• -3 returns the third character from the end, which is h.
• -6 refers to the first character because the string has six characters.

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Example 4: Understanding Negative Indices #

main.py

word = "Python"

print(word[-4])

Output #

t

Explanation #

The characters in "Python" are indexed as follows:

Positive Index	Character	Negative Index
0	P	-6
1	y	-5
2	t	-4
3	h	-3
4	o	-2
5	n	-1

• Therefore, word[-4] returns t.

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Example 5: User Input #

main.py

name = input("Enter your name: ")

print(name[-1])

Sample Input #

Alice

Output #

e

Explanation #

• The user enters a string.
• name[-1] retrieves the last character.
• The last character of "Alice" is e.

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Example 6: Negative Indexing on a Numeric String #

main.py

number = "123456"

print(number[-2])

Output #

5

Explanation #

• Each digit is treated as a character.
• -2 refers to the second last character.
• The returned character is '5'.

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Example 7: Combining Positive and Negative Indexing #

main.py

text = "Python"

print(text[0])
print(text[-1])

Output #

P
n

Explanation #

• Positive indexing starts from the beginning.
• Negative indexing starts from the end.
• Both methods can be used in the same program.

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Example 8: Storing the Last Character #

main.py

word = "Computer"

last = word[-1]

print(last)

Output #

r

Explanation #

• word[-1] retrieves the last character.
• It is stored in the variable last.
• Printing last displays r.

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Example 9: Checking the Type #

main.py

text = "Python"

character = text[-3]

print(character)
print(type(character))

Output #

h
<class 'str'>

Explanation #

• Negative indexing returns a single character.
• A single character is still of type str.
• Python does not have a separate character data type.

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Example 10: Accessing Every Character from the End #

main.py

word = "CAT"

print(word[-1])
print(word[-2])
print(word[-3])

Output #

T
A
C

Explanation #

• -1 returns the last character.
• -2 returns the second last character.
• -3 returns the first character.
• This demonstrates how negative indexing moves backward through the string.

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Common Mistakes #

1. Assuming -1 Refers to the First Character #

Incorrect

word = "Python"

print(word[-1])

Incorrect Expectation #

P

Actual Output #

n

Reason

Negative indexing starts from the end of the string.
-1 always refers to the last character.

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2. Accessing an Invalid Negative Index #

Incorrect

word = "Python"

print(word[-7])

Output #

IndexError: string index out of range

Reason

The string contains only six characters.
The valid negative indices are -1 through -6.

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3. Using a Floating-Point Index #

Incorrect

word = "Python"

print(word[-2.0])

Output #

TypeError: string indices must be integers

Reason

String indices must always be integers.

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4. Accessing an Empty String #

Incorrect

text = ""

print(text[-1])

Output #

IndexError: string index out of range

Reason

An empty string contains no characters.
Therefore, no valid negative index exists.

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Best Practices #

• Use negative indexing when accessing characters near the end of a string.
• Remember that -1 always refers to the last character.
• Verify that the string is not empty before accessing negative indices.
• Use positive indexing when accessing characters near the beginning of a string.
• Choose the indexing method that makes your code easier to read.

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Key Points to Remember #

• Negative indexing accesses characters from the end of a string.
• The last character has index -1.
• The second last character has index -2.
• Positive and negative indexing can be used together.
• Indexed characters are strings of length 1.
• Accessing an invalid negative index raises an IndexError.
• String indices must always be integers.