Merging on index in Pandas - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to merge two DataFrames on their indexes.

Pandas

merged = df1.merge(df2, left_index=[1], right_index=True)

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

AFalse

BNone

CTrue

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using left_index=False will not merge on the index.

Forgetting to set right_index=True if merging on both indexes.

Setting left_index=True tells pandas to use the index of df1 for merging.

2fill in blank

medium

Complete the code to merge two DataFrames on their indexes with an outer join.

Pandas

merged = df1.merge(df2, left_index=True, right_index=True, how=[1])

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

A'inner'

B'outer'

C'left'

D'right'

Attempts:

3 left

💡 Hint

Common Mistakes

Using how='inner' excludes rows not matching in both DataFrames.

Forgetting to set left_index and right_index to True.

The how='outer' parameter includes all rows from both DataFrames, merging on their indexes.

3fill in blank

hard

Fix the error in the code to merge two DataFrames on their indexes.

Pandas

merged = df1.merge(df2, left_index=True, right_index=[1])

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

AFalse

BNone

C0

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Setting right_index to False or None causes merge to fail on index.

Both left_index and right_index must be set to True to merge on indexes.

4fill in blank

hard

Fill both blanks to merge two DataFrames on their indexes using a left join.

Pandas

merged = df1.merge(df2, left_index=[1], right_index=[2], how='left')

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

ATrue

BFalse

CNone

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Setting either left_index or right_index to False will not merge on index.

Setting both left_index and right_index to True merges on indexes.

5fill in blank

hard

Fill all three blanks to merge two DataFrames on their indexes with suffixes for overlapping columns.

Pandas

merged = df1.merge(df2, left_index=[1], right_index=[2], how=[3], suffixes=('_left', '_right'))

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

ATrue

BFalse

C'inner'

D'outer'

Attempts:

3 left

💡 Hint

Common Mistakes

Using False for index parameters prevents merging on indexes.

Using how='inner' excludes non-matching rows.

Set both index parameters to True and use how='outer' to merge all rows on indexes with suffixes for overlapping columns.