In this article, I’ll show you how to check the version of a Python module (package, library).

These are the eight best ways to check the version of a Python module:

• Method 1: pip show my_package
• Method 2: pip list
• Method 3: pip list | findstr my_package
• Method 4: my_package.__version__
• Method 5: importlib.metadata.version
• Method 6: conda list
• Method 7: pip freeze
• Method 8: pip freeze | grep my_package

Let’s dive into some examples for each of those next!

Method 1: pip show

To check which version of a given Python library, say xyz, is installed, use pip show xyz or pip3 show xyz. For example, to check the version of your NumPy installation, run pip show numpy in your CMD/Powershell (Windows), or terminal (macOS/Linux/Ubuntu).

This will work if your pip installation is version 1.3 or higher—which is likely to hold in your case because pip 1.3 was released a decade ago in 2013!!

Here’s an example in my Windows Powershell for NumPy: I’ve highlighted the line that shows that my package version is 1.21.0:

PS C:\Users\xcent> pip show numpy

Name: numpy

Version: 1.21.0

Summary: NumPy is the fundamental package for array computing with Python.

Home-page: https://www.numpy.org

Author: Travis E. Oliphant et al.

Author-email: None

License: BSD

Location: c:\users\xcent\appdata\local\programs\python\python39\lib\site-packages

Requires:

Required-by: pandas, matplotlib

In some instances, this will not work—depending on your environment. In this case, try those commands before giving up:

python -m pip show numpy

python3 -m pip show numpy

py -m pip show numpy

pip3 show numpy

Of course, replace “numpy” with your particular package name.

Method 2: pip list

To check the versions of all installed packages, use pip list and locate the version of your particular package in the output list of package versions sorted alphabetically.

This will work if your pip installation is version 1.3 or higher.

Here’s an example in my Windows Powershell, I’ve highlighted the line that shows that my package version is 1.21.0:

PS C:\Users\xcent> pip list

Package Version

--------------- ---------

beautifulsoup4 4.9.3

bs4 0.0.1

certifi 2021.5.30

chardet 4.0.0

cycler 0.10.0

idna 2.10

kiwisolver 1.3.1

matplotlib 3.4.2

mss 6.1.0

numpy 1.21.0

pandas 1.3.1

Pillow 8.3.0

pip 21.1.1

pyparsing 2.4.7

python-dateutil 2.8.1

pytz 2021.1

requests 2.25.1

setuptools 56.0.0

six 1.16.0

soupsieve 2.2.1

urllib3 1.26.6

In some instances, this will not work—depending on your environment. Then try those commands before giving up:

python -m pip list

python3 -m pip list

py -m pip list

pip3 list 

Method 3: pip list + findstr on Windows

To check the versions of a single package on Windows, you can chain pip list with findstr xyz using the CMD or Powershell command: pip3 list | findstr numpy to locate the version of your particular package xyz in the output list of package versions automatically.

Here’s an example for numpy:

pip3 list | findstr numpy 1.21.0

Method 4: Library.__version__ Attribute

To check your package installation in your Python script, you can also use the xyz.__version__ attribute of the particular library xyz. Not all packages provide this attribute but as it is recommended by PEP, it’ll work for most libraries.

Here’s the code:

import numpy

print(numpy.__version__)

# 1.21.0

Here’s an excerpt from the PEP 8 docs mentioning the __version__ attribute.

“PEP 8 describes the use of a module attribute called __version__ for recording “Subversion, CVS, or RCS” version strings using keyword expansion. In the PEP author’s own email archives, the earliest example of the use of an __version__ module attribute by independent module developers dates back to 1995.”

Method 5: importlib.metadata.version

The importlib.metadata library provides a general way to check the package version in your Python script via importlib.metadata.version('xyz') for library xyz. This returns a string representation of the specific version. For example, importlib.metadata.version('numpy') returns 1.21.0 in my current environment.

Here’s the code:

import importlib.metadata

print(importlib.metadata.version('numpy'))

# 1.21.0

Method 6: conda list

If you have created your Python environment with Anaconda, you can use conda list to list all packages installed in your (virtual) environment. Optionally, you can add a regular expression using the syntax conda list regex to list only packages matching a certain pattern.

How to list all packages in the current environment?

conda list

How to list all packages installed into the environment 'xyz'?

conda list -n xyz

Regex: How to list all packages starting with 'py'?

conda list '^py'

Regex: How to list all packages starting with 'py' or 'code'?

conda list '^(py|code)'

Method 7: pip freeze

The pip freeze command without any option lists all installed Python packages in your environment in alphabetically order (ignoring UPPERCASE or lowercase). You can spot your specific package if it is installed in the environment.

pip freeze

Output from my local Windows environment with PowerShell (strange packages I know) ;):

PS C:\Users\xcent> pip freeze

asn1crypto==1.5.1

et-xmlfile==1.1.0

openpyxl==3.0.10

For example, I have the Python package openpyxl installed with version 3.0.10.

---

You can modify or exclude specific packages using the options provided in this screenshot:

Method 8: pip freeze + grep on Linux/Ubuntu/macOS

To check the versions of a single package on Linux/Ubuntu/macOS, you can chain pip freeze with grep xyz using the CMD or Powershell command: pip freeze | grep xyz to programmatically locate the version of your particular package xyz in the output list of package versions.

Here’s an example for numpy:

pip freeze | grep scikit-learn

scikit-learn==0.17.1

Related Questions

Check Package Version Python

How to check package version in Python?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your CMD/Powershell (Windows), or terminal (macOS/Linux/Ubuntu).

pip show my_package

Check Package Version Linux

How to check my package version in Linux?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your Linux terminal.

pip show my_package

Check Package Version Ubuntu

How to check my package version in Ubuntu?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your Ubuntu terminal/shall/bash.

pip show my_package

Check Package Version Windows

How to check package version on Windows?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your Windows CMD, command line, or PowerShell.

pip show my_package

Check Package Version Mac

How to check package version on macOS?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your macOS terminal.

pip show my_package

Check Package Version Jupyter Notebook

How to check package version in your Jupyter Notebook?

To check which version of a given Python package is installed, add the line !pip show my_package to your notebook cell where you want to check. Notice the exclamation mark prefix ! that allows you to run commands in your Python script cell. For example, to check the version of your NumPy installation, run !pip show numpy in your macOS terminal.

!pip show my_package

For example, this is a screenshot on how this looks for numpy in a Jupyter Notebook:

Check Package Version Terminal

How to check package version in my terminal?

To check which version of a given Python package is installed, use pip show my_package. For example, to check the version of your NumPy installation, run pip show numpy in your terminal.

pip show my_package

Check Package Version Conda/Anaconda

How to check package version in my conda installation?

Use conda list 'my_package' to list version information about the specific package installed in your (virtual) environment.

conda list 'my_package'

Check Package Version with PIP

How to check package version with pip?

You can use multiple commands to check the package version with PIP such as pip show my_package, pip list, pip freeze, and pip list.

pip show my_package

pip list

pip freeze

pip list

Check Package Version in VSCode or PyCharm

How to check package version in VSCode or PyCharm?

Integrated Development Environments (IDEs) such as VSCode or PyCharm provide a built-in terminal where you can run pip show my_package to check the current version of my_package in the specific environment you’re running the command in.

pip show my_package

pip list

pip freeze

You can type any of those commands in your IDE terminal like so:

Summary

In this article, you’ve learned those best ways to check a Python package version:

• Method 1: pip show my_package
• Method 2: pip list
• Method 3: pip list | findstr my_package
• Method 4: my_package.__version__
• Method 5: importlib.metadata.version
• Method 6: conda list
• Method 7: pip freeze
• Method 8: pip freeze | grep my_package

Thanks for giving us your valued attention — we’re grateful to have you here!

---

Programmer Humor

There are only 10 kinds of people in this world: those who know binary and those who don’t.

~~~

There are 10 types of people in the world. Those who understand trinary, those who don’t, and those who mistake it for binary.

FPDF is a fantastic library for working with PDF documents in PHP. It is the most popular one with a large number of plugins that enhances its core features.

Adding a watermark to a PDF document is a basic need in document editing work. Imagine that you have a project where you need to create a feature-rich PDF document editor project with the sole purpose of managing watermarks.

This PHP script will help you as a foundation code to solve your basic watermarking needs. You can use this as a base and build on top of it if you require more.

I have covered two aspects of adding watermarks.

1. Add a watermark to an existing PDF document.
2. Add a watermark to a new PDF document.

I am also presenting an online demo that watermarks a PDF document using this PHP script.

If you are looking for adding a watermark to a web page with a generated image using PHP, refer to this linked article.

View demo

Add a watermark to an existing PDF document

To add a watermark to an existing PDF document, I am using FPDF and FPDI libraries. FPDF is the foundation and FPDI is used to load and edit an existing document.

FPDI helps to load an existing PDF document and use it as a template in FPDF to create a document.

You need to download both FPDF and FPDI libraries and add it to the project. Refer to the project file structure image below.

existing-pdf-watermark.php

<?php

require_once __DIR__ . '/fpdf/fpdf.php';

require_once __DIR__ . '/FPDI/src/autoload.php'; function addWatermark($x, $y, $watermarkText, $angle, $pdf)

{ $angle = $angle * M_PI / 180; $c = cos($angle); $s = sin($angle); $cx = $x * 1; $cy = (300 - $y) * 1; $pdf->_out(sprintf('q %.5F %.5F %.5F %.5F %.2F %.2F cm 1 0 0 1 %.2F %.2F cm', $c, $s, - $s, $c, $cx, $cy, - $cx, - $cy)); $pdf->Text($x, $y, $watermarkText); $pdf->_out('Q');

} $pdf = new \setasign\Fpdi\Fpdi();

$fileInput = 'example.pdf';

$pages_count = $pdf->setSourceFile($fileInput);

for ($i = 1; $i <= $pages_count; $i ++) { $pdf->AddPage(); $tplIdx = $pdf->importPage($i); $pdf->useTemplate($tplIdx, 0, 0); $pdf->SetFont('Times', 'B', 70); $pdf->SetTextColor(192, 192, 192); $watermarkText = 'CONFIDENTIAL'; addWatermark(105, 220, $watermarkText, 45, $pdf); $pdf->SetXY(25, 25);

}

$pdf->Output();

?>

Add a watermark to a new PDF document

Following PHP script is as simple as it gets. The Header function is used to render the PDF document page header. This is called by the AddPage function.

addWatermark is the key function responsible for creating the watermark. It sets the watermark text and performs the rotation to position it across the document. The X and Y location of where to start the watermark text and its color is defined in the Header function.

You can make adjustments by setting a smaller font, position, color, etc as per your choice.

new-pdf-watermark.php

<?php

require __DIR__ . '/fpdf/fpdf.php'; class PDF extends FPDF

{ function Header() { // setting the font, color and text for watermark $this->SetFont('Times', 'B', 48); $this->SetTextColor(140, 180, 205); $watermarkText = 'New PDF Watermark - PHP'; $this->addWatermark(35, 190, $watermarkText, 45); } function addWatermark($x, $y, $watermarkText, $angle) { $angle = $angle * M_PI / 180; $c = cos($angle); $s = sin($angle); $cx = $x * $this->k; $cy = ($this->h - $y) * $this->k; $this->_out(sprintf('q %.5F %.5F %.5F %.5F %.2F %.2F cm 1 0 0 1 %.2F %.2F cm', $c, $s, - $s, $c, $cx, $cy, - $cx, - $cy)); $this->Text($x, $y, $watermarkText); $this->_out('Q'); }

} $pdf = new PDF();

$pdf->AddPage();

$pdf->SetFont('Arial', '', 12);

$pdfDocumentContent = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. .\n\n";

for ($i = 0; $i < 15; $i ++) { $pdf->MultiCell(0, 5, $pdfDocumentContent, 0, 'J');

}

$pdf->Output();

?>

PHP project structure

I have given the complete PHP project as a free download below. The dependent libraries FPDF and FPDI are not available in the project download zip file. You can download them from their official website and add them to your project as per the given project structure above before adding watermarks.

View demo Download

↑ Back to Top

Problem Formulation and Solution Overview

In this article, you’ll learn how to multiply List Elements by a Number in Python.

This example multiples the first five (5) Prime Numbers by two (2) and return the result.

---

Question: How would we write Python code to multiply the list elements?

We can accomplish this task by one of the following options:

• Method 1: Use List Comprehension
• Method 2: Use Pandas tolist()
• Method 3: Use map() and a lambda()
• Method 4: Use NumPy Array()
• Method 5: Use Slicing

---

Method 1: Use List Comprehension

This method uses List Comprehension to apply a mathematical operation to each element and return the result.

prime_nums = [2, 3, 5, 7, 11]

mult_result = [x * 2 for x in prime_nums]

print(mult_result)

Above declares the first (5) Prime Numbers and saves this List to prime_nums. Next, List Comprehension loops through each element and applies the multiplication operation to each. The output saves to mult_result and is output to the terminal.

[4, 6, 10, 14, 22]

---

Method 2: Use Pandas tolist()

This method requires an additional library to be imported, Pandas, to use the tolist() function.

import pandas as pd prime_nums = [2, 3, 5, 7, 11]

mult_result = pd.Series(prime_nums)

mult_result = (mult_result*2).tolist()

print(mult_result)

Above, imports the Pandas Library. Click here if this requires installation. Then, the first (5) Prime Numbers are declared and saved to prime_nums.

Next, prime_nums is passed as an argument to the pd.Series() function and returns mult_result. The output of mult_result at this point is shown below.

0 2 1 3 2 5 3 7 4 11 dtype: int64

Now, we need to convert this output to a list (tolist()) and apply the multiplication operation to each element. The results save to mult_result and are output to the terminal.

[4, 6, 10, 14, 22]

---

Method 3: Use map and lambda Functions

This method wraps the map(), and lambda functions inside a Python List and calculates the results.

prime_nums = [2, 3, 5, 7, 11]

mult_result = list(map(lambda x: x*2, prime_nums))

print(mult_result)

Above declares the first (5) Prime Numbers and saves them to prime_nums. The next line does the following:

• The map() function is passed the lambda() function as an argument (map(lambda x: x*2, prime_nums)).
• The lambda performs the multiplication operation to each element of prime_nums and saves it to map() as an object similar to below.
  <map object at 0x000001DC99CBBBB0>
• The map() object is then converted to a List.
• The results save to mult_result.

Then, mult_result is output to the terminal.

[4, 6, 10, 14, 22]

---

Method 4: Use Numpy Array()

This method requires an additional library to be imported, NumPy, to use the np.array() function.

import numpy as np prime_nums = [2, 3, 5, 7, 11]

the_result = list(np.array(prime_nums) * 2)

print(the_result)

Above, imports the NumPy Library. Click here if this requires installation. Then the first (5) Prime Numbers are declared and saved to prime_nums.

Next, prime_nums is passed as an argument to np.array() where the multiplication operation is applied to each element. Then, this is converted to a List, saved to the_result and output to the terminal.

[4, 6, 10, 14, 22]

---

Method 5: Use Slicing

This method uses Python’s infamous Slicing! No overhead, and a very pythonic way to resolve the issue.

prime_nums = [2, 3, 5, 7, 11]

prime_nums[:] = [x * 2 for x in prime_nums]

print(prime_nums)

Above declares the first (5) Prime Numbers and saves them to prime_nums.

Then slicing is applied and used in conjunction with List Comprehension to apply the multiplication operation to each element. The results save back to prime_nums and are output to the terminal.

[4, 6, 10, 14, 22]

A Finxter Favorite!

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Summary

These methods of multiplying list elements by a number should give you enough information to select the best one for your coding requirements.

Good Luck & Happy Coding!

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Programmer Humor

Programmer 1: We have a problem
Programmer 2: Let’s use RegEx!
Programmer 1: Now we have two problems

… yet – you can easily reduce the two problems to zero as you polish your “RegEx Superpower in Python“.