String Traversal and Character Access in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print each character in the string word using a for loop.

DSA Python

word = "hello"
for [1] in word:
    print([1])

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Achar

Bi

Cword

Dindex

Attempts:

3 left

💡 Hint

Common Mistakes

Using the string variable name itself in the loop variable.

Using an index variable without accessing characters by index.

We use a variable name like char to represent each character in the string as we loop through it.

2fill in blank

medium

Complete the code to print the character at index 2 of the string word.

DSA Python

word = "world"
print(word[1])

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A2

B[1]

C[2]

D[3]

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses instead of square brackets.

Using the wrong index number.

Indexing in strings starts at 0, so index 2 is the third character.

3fill in blank

hard

Fix the error in the code to print all characters of text using a while loop.

DSA Python

text = "data"
i = 0
while i < len(text):
    print(text[1])
    i += 1

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A[i]

B(i)

C{i}

Di

Attempts:

3 left

💡 Hint

Common Mistakes

Using parentheses or braces instead of square brackets for indexing.

Not incrementing the index variable.

To access characters by index, use square brackets with the index variable.

4fill in blank

hard

Fill both blanks to create a dictionary that maps each index of word to its character.

DSA Python

word = "code"
index_map = { [1]: [2] for [1] in range(len(word)) }

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Ai

Bword[i]

Cchar

Dindex

Attempts:

3 left

💡 Hint

Common Mistakes

Using the character variable as the loop variable instead of the index.

Swapping the key and value in the dictionary comprehension.

We use i as the index and word[i] as the character at that index.

5fill in blank

hard

Fill all three blanks to create a list of uppercase characters from word that come after the letter 'a'.

DSA Python

word = "alphabet"
result = [[1].upper() for [2] in word if [3] > 'a']

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Achar

Dletter

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the list comprehension.

Not calling upper() on the character.

We use char as the variable for each character in the string and check if it is greater than 'a'.