query() functionIn pandas, the query() function filters data in a DataFrame. It is used to filter rows in a DataFrame.
query(expr,inplace,*kwargs)
expr: This represents the string to be evaluated.inplace: This is used to determine whether or not we want the entire DataFrame to be modified. The default is False.*kwargs: This represents other optional parameters.The following code demonstrates how to use the query() function in pandas:
import pandas as pd# Create a DataFramedf = pd.DataFrame({"name": ["Maria","Paul","Eva","Sadia","Joe","Camila"],"age":[20,22,32,26,29,30],"salary":[2000,2500,4000,3500,4200,3000],"gender":["female","male","female","female","male","female"]})# Filter rows using query()print(df.query("age > 22 and gender == 'male'"))
Line 1: We import the pandas library.
Lines 4–10: We create a DataFrame from a dictionary and store the data in the variable, df.
Line 13: We filter data in the df using the query() function.
Note: To specify a string value in the
query()function, use a single quote.