Merging on multiple keys in Data Analysis Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to merge two DataFrames on columns 'key1' and 'key2'.

Data Analysis Python

merged_df = df1.merge(df2, on=[1])

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

A['key1', 'key2']

B['key1']

C'key1'

D'key2'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a single string instead of a list for multiple keys.

Using only one key when two are needed.

To merge on multiple keys, you pass a list of column names to the on parameter.

2fill in blank

medium

Complete the code to perform a left merge on columns 'city' and 'year'.

Data Analysis Python

result = df_left.merge(df_right, on=[1], how='left')

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

A['city']

B'city'

C'year'

D['city', 'year']

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single column name instead of a list.

Forgetting to specify the how parameter for merge type.

Use a list of columns for merging on multiple keys with on.

3fill in blank

hard

Fix the error in merging on multiple keys by completing the code.

Data Analysis Python

merged = pd.merge(df1, df2, on=[1])

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

A'key1,key2'

B['key1', 'key2']

C'key1'

D'key2'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a single string with comma-separated keys.

Passing only one key when two are needed.

The on parameter must be a list of column names, not a single string with commas.

4fill in blank

hard

Fill both blanks to create a merged DataFrame on 'state' and 'month' with an inner join.

Data Analysis Python

merged_df = df1.merge(df2, on=[1], how=[2])

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

A['state', 'month']

B'outer'

C'inner'

D['month', 'state']

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of a list for on.

Using the wrong join type in how.

Use a list of keys for on and specify how='inner' for an inner join.

5fill in blank

hard

Fill all three blanks to merge on 'country' and 'year' with a right join and suffixes '_left' and '_right'.

Data Analysis Python

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

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

A['country', 'year']

B'right'

C'_left'

D'inner'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing suffixes as strings instead of a tuple.

Using incorrect join type in how.

Using a string instead of a list for on.

Use a list for on, specify how='right', and set suffixes as a tuple with '_left' and '_right'.