77 lines
3.8 KiB
Markdown
77 lines
3.8 KiB
Markdown
---
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title: Python Using Pip
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---
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We have seen how to use `import` statements to `import` various modules and to use them in our programs. Python itself comes with several built-in modules, but the Python community has more to offer.
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> It's the modules that make Python so powerful!
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Third party modules add so much more functionality to Python. Now we would learn how to install these modules so that we can use those in our programs.
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The simplest way to install these modules is by using `pip`.
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pip install <module_name>
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If you have used `npm`, then you can think of it as _npm_ of Python.
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Side note: The difference is that with npm, `npm install` by default installs packages locally to a project, whereas `pip install` by default installs globally. To install modules locally, you need to create and activate what is called a [virtual environment](http://docs.python-guide.org/en/latest/dev/virtualenvs/), so `pip install` installs to the folder where that virtual environment is located, instead of globally (which may require administrator privileges).
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Last time, in <a>`import-statements`</a> wiki we used `requests` module as an example. As it is a third party module we have to install it separately after installing python.
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Installing it would be as simple as `pip install requests` . You can even pass various arguments along with it. The one that you'll come across more often is `--upgrade`. You can upgrade a python module by :
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pip install <module_name> --upgrade
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For example, to upgrade the requests module to its latest version would be as simple as `pip install requests --upgrade`.
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To update pip itself, you can use `pip install --upgrade pip`
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To find other useful commands for pip, use `pip help`. This will give you a list of useful commands and arguments you can use, such as `uninstall`, `list` or `search`.
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Before using `pip`, you will need to install it (it's quite simple). You can install it from <a href='https://bootstrap.pypa.io/get-pip.py' target='_blank' rel='nofollow'>here</a>
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Just click on the link. And save the file as `get-pip.py` _Please don't forget the `.py` extension._ And run it.
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An alternative to using pip would be to try <a href='https://bootstrap.pypa.io/ez_setup.py' target='_blank' rel='nofollow'>`easy_install`</a>.
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Using `easy_install` is also simple. The syntax is:
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easy_install <module_name>
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However, `pip` is more popular than using `easy_install`, and `easy_install` is <a href='https://setuptools.readthedocs.io/en/latest/easy_install.html'> deprecated</a>.
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**Note:** On some systems where both Python 2 & Python 3 is installed, `pip` and `pip3` will do different things. `pip` installs the Python 2 version of the package, and `pip3` will install the Python 3 version of the package. For more information on the difference between Python 2 & 3, see [this](https://guide.freecodecamp.org/python/python-2-vs-python-3) guide.
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You can check the `pip` version by doing `pip --version` and/or `pip3 --version`:
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pip3 --version
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pip 18.0 from /usr/local/lib/python3.5/dist-packages/pip (python 3.5)
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We can also create a txt file containing a list of modules which should be installed using pip.
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For example, we could create the file `requirements.txt` and its content:
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Kivy-Garden==0.1.4
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macholib==1.5.1
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idna==2.6
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geoip2nation==0.1.2
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docutils>=0.14
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Cython
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In this file, we could also set a version for the installation.
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After this, by invoking pip with:
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pip install -r <FILE CONTAINING MODULES>
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OR IN OUR CASE
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pip install -r requirements.txt
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Should install all the modules listed on the file.
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If you need to know which packages you have installed (along with their versions) you
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can use the list command:
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pip list
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This will come in handy when installing packages with prerequisites such as torch or tensorflow.
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