Python tutorial for windows

Once VS Code has been installed, you must also install the Python extension. Python is an interpreted language, and in order to run Python code, you must tell VS Code which interpreter to use. We recommend using the most recent version of Python unless you have a specific reason for choosing something different.

You can also use the Select Python Environment option on the bottom Status Bar if available it may already show a selected interpreter. The command presents a list of available interpreters that VS Code can find automatically, including virtual environments. If you don't see the desired interpreter, see Configuring Python environments.

The default terminal is PowerShell. Try the Python interpreter out by entering: print "Hello World". Python will return your statement "Hello World". If you plan to collaborate with others on your Python code, or host your project on an open-source site like GitHub , VS Code supports version control with Git.

You first need to install Git to power the Source Control panel. Download and install Git for Windows from the git-scm website. An Install Wizard is included that will ask you a series of questions about settings for your Git installation. We recommend using all of the default settings, unless you have a specific reason for changing something. If you've never worked with Git before, GitHub Guides can help you get started.

Python is an interpreted language. In contrast to compiled languages, in which the code you write needs to be translated into machine code in order to be run by your computer's processor, Python code is passed straight to an interpreter and run directly. You just type in your code and run it. Let's try it! With your PowerShell command line open, enter python to run the Python 3 interpreter. Some instructions prefer to use the command py or python3 , these should also work.

There are several built-in methods that allow you to make modifications to strings in Python. You use def keyword to create functions in Python. A function that calls itself is known as recursive function and this process is called recursion.

Every recursive function must have a base condition that stops the recursion or else the function calls itself infinitely. Visit Python recursion to learn more. In Python, you can define functions without a name. These functions are called lambda or anonymous function. To create a lambda function, lambda keyword is used. We use lambda functions when we require a nameless function for a short period of time.

Lambda functions are used along with built-in functions like filter , map etc. A file containing Python code, for e. You can import specific names from a module without importing the module as a whole. Here is an example. You can use open function to open a file. In order to write into a file in Python, we need to open it in write 'w' , append 'a' or exclusive creation 'x' mode.

Here, we have used with statement to open a file. This ensures that the file is closed when the block inside with is exited. There are various methods available for this purpose. We can use the read size method to read in size number of data. A directory or folder is a collection of files and sub directories.

Python has the os module , which provides many useful methods to work with directories and files. Visit Python Directory to learn more. Errors that occur at runtime are called exceptions. They occur, for example, when a file we try to open does not exist FileNotFoundError , dividing a number by zero ZeroDivisionError etc.

Visit this page to learn about all built-in exceptions in Python. If exceptions are not handled, an error message is spit out and our program come to a sudden, unexpected halt. In Python, exceptions can be handled using try statement. When exceptions are caught, it's up to you what operator to perform. To learn about catching specific exceptions and finally clause with try statement, visit Python exception handling.

Also, you can create user-defined exceptions in Python. For that, visit Python Custom Exceptions. Everything in Python is an object including integers, floats, functions, classes, and None. Let's not focus on why everything in Python is an object. For that, visit this page. Rather, this section focuses on creating your own classes and objects. Object is simply a collection of data variables and methods functions that act on data.

And, class is a blueprint for the object. As soon as you define a class, a new class object is created with the same name. This class object allows us to access the different attributes as well as to instantiate new objects of that class. You may have noticed the self parameter in function definition inside the class but, we called the method simply as ob.

It still worked. This is because, whenever an object calls its method, the object itself is passed as the first argument. So, ob. This method is automatically called when an object is instantiated. Visit Python Class and Object to learn more. Inheritance refers to defining a new class with little or no modification to an existing class.

Let's take an example:. Notice that we are able to call method of base class displayMammalFeatures from the object of derived class d. To learn more about inheritance and method overriding, visit Python Inheritance. We also suggest you to check multiple inheritance and operator overloading if you are interested.

Iterator in Python is simply an object that can be iterated upon. An object which will return data, one element at a time.

An object is called iterable if we can get an iterator from it. Most of built-in containers in Python like: list, tuple, string etc. Alternatively, it will be available from any Command Prompt or PowerShell session by typing python. Further, pip and IDLE may be used by typing pip or idle. IDLE can also be found in Start. All three commands are also available with version number suffixes, for example, as python3.

It is recommended to make sure that pip and idle are consistent with whichever version of python is selected. Virtual environments can be created with python -m venv and activated and used as normal. If you have installed another version of Python and added it to your PATH variable, it will be available as python.

To access the new installation, use python3. The py. Uninstalling will remove all packages you installed directly into this Python installation, but will not remove any virtual environments. Because of restrictions on Microsoft Store apps, Python scripts may not have full write access to shared locations such as TEMP and the registry.

Instead, it will write to a private copy. If your scripts must modify the shared locations, you will need to install the full installer. Visit nuget. What follows is a summary that is sufficient for Python developers. With the tool, the latest version of Python for bit or bit machines is installed using:. To select a particular version, add a -Version 3. The output directory may be changed from.

By default, the subdirectory is named the same as the package, and without the -ExcludeVersion option this name will include the specific version installed. Inside the subdirectory is a tools directory that contains the Python installation:. In general, nuget packages are not upgradeable, and newer versions should be installed side-by-side and referenced using the full path. Alternatively, delete the package directory manually and install it again. Many CI systems will do this automatically if they do not preserve files between builds.

This contains a MSBuild properties file python. Including the settings will automatically use the headers and import libraries in your build.

The package information pages on nuget. The embedded distribution is a ZIP file containing a minimal Python environment. It is intended for acting as part of another application, rather than being directly accessed by end-users. The standard library is included as pre-compiled and optimized. The embedded distribution does not include the Microsoft C Runtime and it is the responsibility of the application installer to provide this.

Third-party packages should be installed by the application installer alongside the embedded distribution. Using pip to manage dependencies as for a regular Python installation is not supported with this distribution, though with some care it may be possible to include and use pip for automatic updates. An application written in Python does not necessarily require users to be aware of that fact.

The embedded distribution may be used in this case to include a private version of Python in an install package. Depending on how transparent it should be or conversely, how professional it should appear , there are two options.

Using a specialized executable as a launcher requires some coding, but provides the most transparent experience for users. With a customized launcher, there are no obvious indications that the program is running on Python: icons can be customized, company and version information can be specified, and file associations behave properly.

The simpler approach is to provide a batch file or generated shortcut that directly calls the python. In this case, the application will appear to be Python and not its actual name, and users may have trouble distinguishing it from other running Python processes or file associations. With the latter approach, packages should be installed as directories alongside the Python executable to ensure they are available on the path.

With the specialized launcher, packages can be located in other locations as there is an opportunity to specify the search path before launching the application. Applications written in native code often require some form of scripting language, and the embedded Python distribution can be used for this purpose.

In general, the majority of the application is in native code, and some part will either invoke python. For either case, extracting the embedded distribution to a subdirectory of the application installation is sufficient to provide a loadable Python interpreter.

As with the application use, packages can be installed to any location as there is an opportunity to specify search paths before initializing the interpreter. Otherwise, there is no fundamental differences between using the embedded distribution and a regular installation. Besides the standard CPython distribution, there are modified packages including additional functionality. The following is a list of popular versions and their key features:.

Popular scientific modules such as numpy, scipy and pandas and the conda package manager. Note that these packages may not include the latest versions of Python or other libraries, and are not maintained or supported by the core Python team. To run Python conveniently from a command prompt, you might consider changing some default environment variables in Windows.

If you regularly use multiple versions of Python, consider using the Python Launcher for Windows. Windows allows environment variables to be configured permanently at both the User level and the System level, or temporarily in a command prompt.

To temporarily set environment variables, open Command Prompt and use the set command:. These changes will apply to any further commands executed in that console, and will be inherited by any applications started from the console. Including the variable name within percent signs will expand to the existing value, allowing you to add your new value at either the start or the end. Modifying PATH by adding the directory containing python. In this dialog, you can add or modify User and System variables.

To change System variables, you need non-restricted access to your machine i. Administrator rights. Windows will concatenate User variables after System variables, which may cause unexpected results when modifying PATH.

Besides using the automatically created start menu entry for the Python interpreter, you might want to start Python in the command prompt. The installer has an option to set that up for you. This allows you to type python to run the interpreter, and pip for the package installer. Thus, you can also execute your scripts with command line options, see Command line documentation. You need to set your PATH environment variable to include the directory of your Python installation, delimited by a semicolon from other entries.

An example variable could look like this assuming the first two entries already existed :. Python uses it for the default encoding of text files e. Classes 9. A Word About Names and Objects 9. Python Scopes and Namespaces 9. Scopes and Namespaces Example 9. A First Look at Classes 9. Class Definition Syntax 9. Class Objects 9. Instance Objects 9. Method Objects 9.

Class and Instance Variables 9. Random Remarks 9. Inheritance 9. Multiple Inheritance 9. Private Variables 9. Odds and Ends 9. Iterators 9. Generators 9. Generator Expressions Brief Tour of the Standard Library Operating System Interface File Wildcards Command Line Arguments Error Output Redirection and Program Termination String Pattern Matching Mathematics Internet Access Dates and Times Data Compression Performance Measurement Quality Control Batteries Included Output Formatting Templating Working with Binary Data Record Layouts Multi-threading Logging