pandas.DataFrame.query# DataFrame. query (expr, *, inplace = False, ** kwargs) [source] # Query the columns of a DataFrame with a boolean expression. Parameters: expr str. The query string to evaluate. You can refer to variables in the environment by prefixing them with an ‘@’ character like @a + b.

Mar 29, 2023 · Pandas query() method Syntax. Syntax: DataFrame.query(expr, inplace=False, **kwargs) Parameters: expr: Expression in string form to filter data. inplace: Make changes in the original data frame if True; kwargs: Other keyword arguments. Return type: Filtered Data frame. Pandas DataFrame query() Method

The query() method allows you to query the DataFrame. The query() method takes a query expression as a string parameter, which has to evaluate to either True of False. It returns the DataFrame where the result is True according to the query expression.

Feb 19, 2024 · One of its powerful features, the query() method, allows for efficient and concise querying of DataFrame objects. This approach not only simplifies the syntax for filtering data but also often results in more readable code. This tutorial is designed to guide you through the powerful DataFrame.query() method in Pandas through 5 practical ...

Oct 26, 2022 · In this tutorial, you’ll learn how to use the Pandas query function to filter a DataFrame in plain English. One of the many perks of the function is the ability to use SQL-like filter statements to filter your dataset.

Jan 29, 2017 · @x.name - @ helps .query() to understand that x is an external object (doesn't belong to the DataFrame for which the query () method was called). In this case x is a DataFrame. It could be a scalar value as well. I hope this small demonstration will help you to understand it: a b c. a x. a b c. Scalar x: a b c.

Aug 30, 2021 · Syntax of the DataFrame.query() function in pandas. pandas.DataFrame.query(expr, inplace=False, **kwargs) expr = It is a string that contains the logical expression according to which the rows of the pandas DataFrame is selected (when the value of expr=True).

Jan 7, 2025 · Pandas.DataFrame.query() function filters rows from a DataFrame based on a specified condition. Pandas.DataFrame.query() offers a powerful and concise syntax for filtering DataFrame rows, resembling SQL queries, enhancing code readability and maintainability.

In this article, I’ll explain how pandas query works in Python with the best examples. What is pandas.query()? The query() method in pandas allows for querying DataFrames and Series using a readable string-based syntax.

Jan 25, 2024 · In pandas, the query() method allows you to extract DataFrame rows by specifying conditions through a query string, using comparison operators, string methods, logical combinations, and more. For details on extracting rows and columns using Boolean indexing, see the following article.