PyCharm 3.4.0 Web Help

When the Extract Method refactoring is invoked , PyCharm analyses the selected block of code and detects variables that are the input for the selected code fragment and the variables that are output for it.

Before After
import math

class Solver:
def demo(self):
    a = 3
    b = 25
    c = 46
    root1 = (-b + math.return_type_of_sqrt(b**2 - 4*a*c)) / (2*a)
    root2 = (-b - math.return_type_of_sqrt(b**2 - 4*a*c)) / (2*a)
    print(root1, root2)

Solver().demo()
                
import math

class Solver:
def eval_roots(self, a, b, c):
    d = b**2 - 4*a*c
    root1 = (-b + math.sqrt(d)) / (2*a)
    root2 = (-b - math.sqrt(d)) / (2*a)
    return root1, root2

def demo(self):
    a = 3
    b = 25
    c = 52
    root1, root2 = self.eval_roots(a, b, c)
    print(root1, root2)
        
Solver().demo()
                
py_extract_substring1 py_extract_substring_method
To extract a method
  1. In the editor, select a block of code to be transformed into a method or a function.

    Tip

    The code fragment to form the method does not necessarily have to be a set of statements. It may also be an expression used somewhere in the code.

  2. On the main menu or on the context menu of the selection, choose Refactor | Extract | Method or press Ctrl+Alt+MCtrl+Alt+MCtrl+Alt+MCtrl+Alt+MCtrl+Alt+MCtrl+Alt+MShift+Alt+MShift+Alt+MAlt Command MAlt Command MAlt Command M.
  3. In the Extract Method dialog box that opens, specify the name of the new method.
  4. In the Parameters area, do the following:
    • Specify the variables to be passed as method parameters by selecting/clearing the corresponding check boxes.
    • Rename the desired parameters, by double-clicking the corresponding parameter lines and entering new names.
  5. Check the result in the Signature Preview pane and click OK to create the method.

    Tip

    3.0+
    If duplicate code fragments are encountered, PyCharm suggests to replace them with the calls to the extracted method:

    py_extract_method_duplicates

    The selected code fragment will be replaced with a method call.

See Also

Reference:

Web Resources: