How to reverse a DataFrame in Python Polars
Polars, a DataFrame library entirely coded in Rust, offers Python developers a scalable and efficient data handling framework as an alternative to pandas. It boasts extensive features for streamlined data manipulation and analysis tasks.
Importing the library
We use the following code to import the polars library:
import polars as pl
The reverse function
We can use the DataFrame.reverse function to revert a given DataFrame. This functionality helps to attain the reversal form of the provided DataFrame.
Syntax
Here’s the syntax of the reverse() function:
DataFrame.reverse()
Return value
The function returns a reverted DataFrame, which can be stored and utilized for further implementations.
Coding example
Let’s look at a coding example of the DataFrame.reverse function.
Note: Click the “Run” button to test the code.
import polars as pldf = pl.DataFrame({"key": [["a", "b", "c"],["d", "e", "f"],["g", "h", "i"]],"val": [[1, 2, 3],[4, 5, 6],[7, 8, 9]]})print("- Original DataFrame\n", df)print("- Reversed DataFrame\n", df.reverse())
Code explanation
Let’s learn about the implementation line by line:
-
Line 1: We import the
polarslibrary and give it theplalias to make it easier to refer to in the code. -
Line 3: We create the DataFrame named
df. -
Line 4–12: We initialize the DataFrame with two columns:
"key"and"val". The"key"column contains the lists of strings, and the"val"column contains the lists of integers. -
Line 13: We display the original DataFrame.
-
Line 14: We call the
reverse()method on the DataFramedfand print the result. Thereverse()method reverses the order of the rows in the DataFrame. It does not modify the original DataFrame but returns a new DataFrame with the rows reversed.
Unlock your potential: Polars in Python series, all in one place!
To continue your exploration of Polars, check out our series of Answers below:
How to scale and normalize data in Python using Polars
Learn how to transform raw data using Python's Polars library to scale it (0-1) and normalize it (mean 0, std 1).What is DataFrame.clear function in Polars Python?
Learn how to use Polars'DataFrame.clear()to create a null-filled copy, either empty ifn=0or withnnull rows.How to reverse a DataFrame in Polars Python?
Learn how to use Polars, a Rust-based DataFrame library for Python, which offers areverse()function to efficiently revert DataFrame rows, providing an alternative to pandas.How to rename the column names in Polars Python?
Learn how to use Polars'rename()function to efficiently rename DataFrame columns using key-value pairs, enhancing data management and processing.What is Polars library in Python?
Learn how Polars, a fast DataFrame library in Rust for Python, offers high-performance data manipulation and analysis similar to Pandas.How to concatenate two Dataframes in Polars Python
Learn how Polars, leveraging Rust, offers efficient DataFrame concatenation in Python with theconcat()method.How to perform a transpose of a Python Polars DataFrame
Learn how to use Polars'DataFrame.transpose()to efficiently transpose DataFrames, with options for including headers and custom column names, enhancing data manipulation capabilities.How to check the polars version in Python
Learn how to ensure the correct Polars version by usingpip3 show polarsor by printingpl.__version__in Python.What is DataFrame.update function in Polars Python?
Learn how to use theupdate()function in Polars to merge two DataFrames, updating the target with non-null values from the source, and supporting various join strategies.
Free Resources