
For a few of our examples, we have also explained the second way of filtering rows without using query() method for comparison purposes.īelow we have imported pandas and numpy libraries that we'll use in our tutorial. We have created many different examples to explain different conditions covering the majority of scenarios. The query() method used eval() method behind the scene to evaluate Python expressions.Īs a part of this tutorial, we'll explain how we can use Python expressions to filter rows of pandas dataframe using query() method. Learning by Reading We have created 14 tutorial pages for you to learn more about Pandas. We need to provide expression as a string to query() method. The expression can use column names of pandas dataframe inside it and compare it against scalar, local variable, etc to make decisions.

To use python expressions with pandas dataframe, it provides a method named query() which takes as input python expression and filters rows of dataframe based on the condition specified through expression.
#PANDAS PYTHON CODE#
It can make code quite easy to understand if we can filter rows of pandas dataframe by providing python expressions specifying some conditions to filter rows. What if we can use python expressions to filter rows of pandas dataframe. Pandas dataframes are the most commonly used data structure to store and manipulate tabular data in Python. Python provides constructs like '>,=,<=,=,!=,~, &, |,~' etc for performing various conditions. Labels need not be unique but must be a hashable type.
#PANDAS PYTHON SERIES#
Pandas Series is nothing but a column in an excel sheet. The axis labels are collectively called index. We can even compare different variables using expressions and make decisions based on that. Pandas Series is a one-dimensional labeled array capable of holding data of any type (integer, string, float, python objects, etc.). We can check for conditions like the presence of variables in sequences or scalar values in sequences. Additionally, it has the broader goal of becoming the most powerful and flexible open source data analysis / manipulation tool available in any language.

It can let us check for various conditions like greater than, less than, equal to, not equal to, etc. pandas aims to be the fundamental high-level building block for doing practical, real world data analysis in Python. Python expressions lets us check for conditions and make decisions based on the result.

It can be seen as a table that organizes data into rows and columns, making it a. Pandas query(): Query Pandas DataFrame using Python Expressions ¶ pandas DataFrame is a way to represent and work with tabular data.
