eval() for expression evaluation in Pandas - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to evaluate the expression '2 + 3' using eval().

Pandas

result = eval([1])
print(result)

Drag options to blanks, or click blank then click option'

A"2 + 3"

B2 + 3

C'2 + 3'

D2 * 3

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the expression without quotes causes a syntax error.

Using single quotes without escaping inside eval can cause errors.

The eval() function expects a string expression to evaluate. So the expression must be passed as a string, like "2 + 3".

2fill in blank

medium

Complete the code to evaluate the expression stored in the variable 'expr' using eval().

Pandas

expr = '10 / 2'
result = eval([1])
print(result)

Drag options to blanks, or click blank then click option'

Aexpr

B"expr"

C'expr'

D10 / 2

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the variable name as a string instead of the variable itself.

Trying to evaluate the expression without storing it in a variable.

Since expr is a variable holding the string expression, we pass it directly to eval() without quotes.

3fill in blank

hard

Fix the error in the code to evaluate the expression 'df["A"] + df["B"]' using pandas.eval().

Pandas

import pandas as pd
df = pd.DataFrame({'A': [1, 2], 'B': [3, 4]})
result = pd.eval([1])
print(result)

Drag options to blanks, or click blank then click option'

Adf.A + df.B

Bdf['A'] + df['B']

C"df['A'] + df['B']"

D'df["A"] + df["B"]'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the expression as a Python expression instead of a string.

Using inconsistent quotes causing syntax errors.

pandas.eval() expects the expression as a string. So the expression must be passed as a string with proper quotes.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that uses eval() to filter words longer than 3 characters.

Pandas

words = ['cat', 'lion', 'dog', 'elephant']
lengths = {word: [1] for word in words if [2]

Drag options to blanks, or click blank then click option'

Alen(word)

Blen(word) > 3

Cword

Dword > 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using the word itself instead of its length.

Filtering by comparing the word string to a number.

The dictionary comprehension maps each word to its length using len(word). The filter keeps words where len(word) > 3.

5fill in blank

hard

Fill all three blanks to create a pandas.eval() expression that calculates the sum of columns 'X' and 'Y' for rows where 'Z' > 5.

Pandas

import pandas as pd
df = pd.DataFrame({'X': [1, 2, 3], 'Y': [4, 5, 6], 'Z': [6, 4, 7]})
result = df.loc[df.eval([1]), [2] + [3]]
print(result)

Drag options to blanks, or click blank then click option'

A"Z > 5"

B'X'

C'Y'

D'Z'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the filter expression without quotes.

Using wrong column names or missing quotes.

The eval() expression filters rows where Z > 5. Then columns 'X' and 'Y' are selected and summed.