Shortcut to comment out multiple lines in Python

We often need to comment out block of codes in python while testing or debugging the code. When a block is turned into a python comment, it doesn’t contribute in output of the program and helps to determine which function or block is generating error in the program. In this article, we will look at some shortcut to comment out multiple lines of code at once in different python IDEs. Lets see examples for each IDE one by one.

Shortcut to comment out multiple lines in Spyder

In spyder python IDE, we can comment a single line of code by selecting the line and then using the key combination ctrl+1 . This will turn the selected single line to a comment as shown below. The function given in the example adds a number and its square to a python dictionary as as key-value pair.

print("This line will be commented out.")
def add_square_to_dict(x,mydict):
    a=x*x
    mydict[str(x)]=a
    return mydict
    

After pressing ctrl+1:

#print("This line will be commented out.")
def add_square_to_dict(x,mydict):
    a=x*x
    mydict[str(x)]=a
    return mydict
    

The shortcut to comment out multiple lines of code in spyder IDE is to first select all the lines which need to be commented out and then the key combination ctrl+4 is pressed. This turns the entire selected lines into a python comment as shown below.

  class MyNumber():
      """This is the docstring of this class.
      
      It describes what this class does and all its attributes."""
      def __init__(self, value):
          self.value=value
      def increment(self):
          """This is the docstring for this method.
          
          It describes what the method does, what are its calling conventions and
          what are its side effects"""
          self.value=self.value+1
          return self.value
  print (MyNumber.increment.__doc__)

After pressing ctrl+4:

# =============================================================================
# 
#   class MyNumber():
#       """This is the docstring of this class.
#       
#       It describes what this class does and all its attributes."""
#       def __init__(self, value):
#           self.value=value
#       def increment(self):
#           """This is the docstring for this method.
#           
#           It describes what the method does, what are its calling conventions and
#           what are its side effects"""
#           self.value=self.value+1
#           return self.value
#   print (MyNumber.increment.__doc__)
# =============================================================================

We can also use ctrl+1 to uncomment the lines after selecting them when they are commented out or comment out the lines after selecting them to comment them out. In some versions of Spyder ctrl+5 can be used to uncomment the lines of code.

Shortcut to comment out multiple lines in IDLE

To comment out a block of code in IDLE, we have to first select the line and then press the key combination ctrl+D. This will comment out the selected lines of code as shown below.

 class MyNumber():
         """This is the docstring of this class.
         
         It describes what this class does and all its attributes."""
         def __init__(self, value):
             self.value=value
         def increment(self):
             """This is the docstring for this method.
             
             It describes what the method does, what are its calling conventions and
             what are its side effects"""
             self.value=self.value+1
             return self.value
     print (MyNumber.increment.__doc__)

After pressing ctrl+D:

## class MyNumber():
##         """This is the docstring of this class.
##         
##         It describes what this class does and all its attributes."""
##         def __init__(self, value):
##             self.value=value
##         def increment(self):
##             """This is the docstring for this method.
##             
##             It describes what the method does, what are its calling conventions and
##             what are its side effects"""
##             self.value=self.value+1
##             return self.value
##     print (MyNumber.increment.__doc__)

To uncomment the lines of code, we just have to select the lines and then press ctrl+shift+d. This will uncomment the selected lines.

Shortcut to comment out multiple lines in Jupyter Notebook

We can use ctrl+/ to comment out the selected lines of python code in Jupyter Notebook. This turns selected lines of code into comment as shown below.

     class MyNumber():
         """This is the docstring of this class.
         
         It describes what this class does and all its attributes."""
         def __init__(self, value):
             self.value=value
         def increment(self):
             """This is the docstring for this method.
             
             It describes what the method does, what are its calling conventions and
             what are its side effects"""
             self.value=self.value+1
             return self.value
     print (MyNumber.increment.__doc__)

After pressing ctrl+/:

#      class MyNumber():
#          """This is the docstring of this class.
         
#          It describes what this class does and all its attributes."""
#          def __init__(self, value):
#              self.value=value
#          def increment(self):
#              """This is the docstring for this method.
             
#              It describes what the method does, what are its calling conventions and
#              what are its side effects"""
#              self.value=self.value+1
#              return self.value
#      print (MyNumber.increment.__doc__)

To uncomment the selected lines, we just have to again press ctrl+/.

Comment out multiple lines in Pycharm

If we have to comment out multiple lines of code in Pycharm, we can select the lines to be commented out and then press ctrl+shift+/ . To uncomment the lines, we just have to select the lines and then again press ctrl+shift+/.

Conclusion

In this article, we have seen shortcuts to comment out multiple lines at once in python different IDEs like spyder, IDLE, Jupyter Notebook and PyCharm. Stay tuned for more informative articles.