Pandas Querying Examples

[s2t2]

Add some examples of using pandas dataframe.query, probably to the filtering rows section of the chapter about row operations.

https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.query.html

AI example:

import pandas as pd

# Create a sample DataFrame
df = pd.DataFrame({
    'name': ['john', 'david', 'anna', 'peter'],
    'country': ['USA', 'UK', 'USA', 'UK'],
    'age': [23, 45, 45, 30]
})

target_age = 45

# Query for rows where country is 'USA' and age is greater than 30
result = df.query("country == 'USA' and age > 30")

# Query using an external Python variable
result_var = df.query("age == @target_age")

print(result)
print(result_var)