Part 2. Navigating to a Declaration or Implementation
On this page:
- Preparing an example
- Navigating to declaration
- Navigating to implementation
- Navigating with gutter icons
Preparing an example
Do the following:
- Add package
Animalsunder your project root (Alt+Insert | ).
- Create the following Python files (Alt+Insert | ):
- Open these files for editing (F4) and add the following code:
from Animals.Carnivore import Carnivore from Animals.Herbivore import Herbivore class Mammalia(object): extremities = 4 def feeds(self): print ("milk") def proliferates(self): pass class Marsupial(Mammalia): def proliferates(self): print("poach") class Eutherian(Mammalia): def proliferates(self): print("placenta") class TasmanianDevil(Marsupial, Carnivore): pass class Duckbill(Marsupial, Herbivore): pass class Cat(Carnivore, Eutherian): pass class Tiger(Eutherian,Carnivore): pass class Cow(Eutherian, Herbivore): pass Cat.feeds()
from Animals.Mammal import Mammalia class Carnivore(Mammalia): def food(self): print("meat") pass
from Animals.Mammal import Mammalia class Herbivore (Mammalia): def food(self): print("grass") pass
Navigating to declaration
Place the caret at the method
feeds of the instance of the class
Cat, and press
Ctrl+B. PyCharm jumps to the declaration of the method
which is declared in the class
Navigating to implementation
Now, place caret at the declaration of the class
Mammalia and try to find out which other
classes implement it. To do that, press Ctrl+Alt+B. You see a rather long list of
Ok, choose whichever implementation you need (for example,
), and press Enter. PyCharm navigates to the
selected implementation and places the caret at the class
Should you select, for example
Carnivore, which resides in a separate file, this file would open
in a separate editor tab.
Side note about pin
Presumably, you have already noticed the pin icon in the upper-right corner of the pop-up window. The same icon appears, for example, in the quick documentation lookup (Ctrl+Q). If you click this pin, the whole pop-up window will be "pinned", which in the case of navigation and search means that all the encountered occurrences will be presented in the Find tool window.
Navigating with gutter icons
Finally, let's look at the left gutter. You see there a number of icons with the arrows pointing up or down. What does it mean?
If you hover your mouse pointer over an icon, PyCharm will show the list of child classes or overriding methods (in case of the down arrow), or the parent classes (in case of the up arrow):
What happens, if you click an icon? If a certain class is subclassed, or a method is overridden in more than one class, PyCharm will suggest to select the desired target from the list:
After that, PyCharm jumps to the selected target, and places the caret at the class (method) declaration. If there is only one superclass/subclass, or method, then such a navigation is done silently.