Pandas: Use a local variable within a query

Last update on May 01 2025 12:54:19 (UTC/GMT +8 hours)

75. Use Local Variable Within a Query

Write a Pandas program to use a local variable within a query.

Sample Solution :

Python Code :

import pandas as pd
df = pd.DataFrame({'W':[68,75,86,80,66],'X':[78,85,96,80,86], 'Y':[84,94,89,83,86],'Z':[86,97,96,72,83]});
print("Original DataFrame")
print(df)
maxx = df["W"].max()
print("\nValues which are less than maximum value of 'W' column")
print(df.query("W < @maxx"))

Sample Output:

Original DataFrame
    W   X   Y   Z
0  68  78  84  86
1  75  85  94  97
2  86  96  89  96
3  80  80  83  72
4  66  86  86  83

Values which are less than maximum value of 'W' column
    W   X   Y   Z
0  68  78  84  86
1  75  85  94  97
3  80  80  83  72
4  66  86  86  83

For more Practice: Solve these Related Problems:

Write a Pandas program to define a local variable and then use it within a DataFrame query to filter rows based on a threshold.
Write a Pandas program to use a locally defined constant in a query() call and then output the filtered DataFrame.
Write a Pandas program to incorporate a local variable into a query that compares two columns and then validate the result.
Write a Pandas program to define a variable externally and then reference it inside a DataFrame query to perform conditional filtering.

Go to:

Previous: Write a Pandas program to fill missing values in time series data.
Next: Write a Pandas program to clean object column with mixed data of a given DataFrame using regular expression.

Python-Pandas Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.