PyCharm 2019.3 Help

Step 1. Create and run your first Python project

Before you start

Make sure that the following prerequisites are met:

  • You are working with PyCharm CE or Professional .

  • You have installed Python itself. If you're using macOS or Linux, your computer already has Python installed. You can get Python from python.org.

Creating a Python project

To get started with PyCharm, let’s write a Python script.

Let’s start our project: if you’re on the Welcome screen, click Create New Project. If you’ve already got a project open, choose File | New Project.

Welcome screen

In this tutorial we’ll create a simple Python script, so we’ll choose Pure Python. This template will create an empty project for us.

Create a new project

Choose the project location. To do that, click the Browse button button next to the Location field, and specify the directory for your project.

Python best practice is to create a virtualenv for each project. To do that, expand the Project Interpreter: New Virtualenv Environment node and select a tool used to create a new virtual environment. Let's choose Virtualenv tool, and specify the location and base interpreter used for the new virtual environment. Select the two check boxes below if necessary.

When you configure a project Python interpreter, you need to specify the path to the Python executable in your system. So, before configuring a project interpreter, you need to ensure that you've downloaded Python and installed it in your system and you're aware of a path to it. You can create several project interpreters based on the same Python executable. This is helpful when you need to create different virtual environments for developing different types of applications. For example, you can create one virtual environment based on Python 3.6 to develop Django applications and another virtual environment based on the same Python 3.6 to work with scientific libraries.

Then click the Create button at the bottom of the New Project dialog.

If you’ve already got a project open, after clicking Create PyCharm will ask you whether to open a new project in the current window or in a new one. Choose Open in current window - this will close the current project, but you'll be able to reopen it later. See the page Opening Multiple Projects for details.

Creating a Python file

Select the project root in the Project tool window, then select File | New ... from the main menu or press Alt+Insert.

Create a Python file

Choose the option Python file from the popup, and then type the new filename.

Creating a new Python file

PyCharm creates a new Python file and opens it for editing.

New Python file

Editing source code

Let's first have a look at the Python file we've just generated.

Immediately as you start typing, you should see that PyCharm, like a pair-programmer, looks over your shoulder and suggests how to complete your line. For example, you want to create a Python class. As you just start typing the keyword, a suggestion list appears:

Create class completion

Choose the keyword class and type the class name (Car here).

PyCharm immediately informs you about the missing colon, then expected indentation:

Create class analysis

Note the stripes in the scrollbar. Hover your mouse pointer over a stripe, and PyCharm shows a balloon with the detailed explanation.

Since PyCharm analyses your code on-the-fly, the results are immediately shown in the inspection indicator on top of the scrollbar. This inspection indication works like a traffic light: when it is green, everything is OK, and you can go on with your code; a yellow light means some minor problems that however will not affect compilation; but when the light is red, it means that you have some serious errors.

Let's continue creating the function __init__: when you just type the opening brace, PyCharm creates the entire code construct (mandatory parameter self, closing brace and colon), and provides proper indentation:

Create class

For the example, let's use this code: (you can either type it yourself, or use the copy button in the top right of the code block here in the help):

class Car: def __init__(self, speed=0): self.speed = speed self.odometer = 0 self.time = 0 def say_state(self): print("I'm going {} kph!".format(self.speed)) def accelerate(self): self.speed += 5 def brake(self): self.speed -= 5 def step(self): self.odometer += self.speed self.time += 1 def average_speed(self): if self.time != 0: return self.odometer / self.time else: pass if __name__ == '__main__': my_car = Car() print("I'm a car!") while True: action = input("What should I do? [A]ccelerate, [B]rake, " "show [O]dometer, or show average [S]peed?").upper() if action not in "ABOS" or len(action) != 1: print("I don't know how to do that") continue if action == 'A': my_car.accelerate() elif action == 'B': my_car.brake() elif action == 'O': print("The car has driven {} kilometers".format(my_car.odometer)) elif action == 'S': print("The car's average speed was {} kph".format(my_car.average_speed())) my_car.step() my_car.say_state()

Running your application

You can right-click the editor, and from the context menu choose to run the script Ctrl+Shift+F10, but we suggest a better solution: since our script contains a main function, there is an icon Run icon in the left gutter in the gutter. If you hover your mouse pointer over it, the available commands show up:

Running a script

If you click this icon, you'll see the popup menu of the available commands. Choose Run Car:

Run command

A console appears in the Run tool window.

Run Tool window

See the sections under Running node for more details about configuring how your code is executed by PyCharm.

Run/debug configuration

When we run the script just now, PyCharm created a temporary run/debug configuration for us. Let’s first save this configuration: go to the run configuration dropdown on the top-right of the editor, and choose Save configuration.

Edit Run/Debug configuration

Afterwards, choose Edit Configurations to have a look at what is happening here.

Run/Debug Configuration

If you’d like to change how your program is executed by PyCharm, this is where you can configure various settings like: command-line parameters, work directory, and more. See run/debug configurations for more details.

If you’d like to start the script using this Run configuration, use the Run button next to the dropdown.

Summary

Congratulations on completing your first script in PyCharm! Let's repeat what you've done with the help of PyCharm:

  • Created a project.

  • Created a file in the project.

  • Created the source code.

  • Ran this source code.

  • Saved the run/debug configuration.

In the next step, learn how to debug your programs in PyCharm.

Last modified: 2 April 2020