Let’s jump right into Python functions and their anatomy in simple English. Before anything else what are functions? They’re like mini-programs within a program that can do some cool stuff for you when called upon, just like having your own personal assistant who does all the grunt work for you!
To create one, use the def keyword followed by the name of your function and enclose it in parentheses. For example:
# This is a simple python script that demonstrates how to create a function and call it.
# First, we use the def keyword to define our function and give it a name, in this case "my_function".
# We also enclose it in parentheses to indicate that it is a function.
def my_function():
# Inside the function, we use the print() function to display a message.
print("Hello from a function")
# Now, we can call our function by simply using its name followed by parentheses.
# This will execute the code inside the function and display the message.
my_function()
# Output: Hello from a function
Notice that we didn’t include any arguments or parameters in this particular function, so when you call it nothing will be passed into the function and it won’t return anything either. But don’t worry functions can do much more than just say hello! Let’s take a look at an example with some parameters:
# This function takes in a parameter called "name"
def my_function(name):
# Prints out a greeting with the value of the "name" parameter
print("Hello, " + name)
# To call this function, we need to pass in an argument for the "name" parameter
# For example, if we want to greet someone named "John", we would call the function like this:
my_function("John")
# This would output: "Hello, John"
In this function we added a parameter called `name`. When you call the function and pass in a value for `name`, it will be stored as an argument within the function. This allows us to customize what our function does based on the input provided!
Now how functions can return values. Here’s an example:
# This function takes in a parameter called `x` and checks if it is greater than 5.
# If it is, it returns the string "Greater than 5".
# If it is not, it returns the string "Less than or equal to 5".
def my_function(x):
if x > 5: # Checks if the value of `x` is greater than 5.
return "Greater than 5" # Returns the string "Greater than 5" if the condition is met.
else:
return "Less than or equal to 5" # Returns the string "Less than or equal to 5" if the condition is not met.
In this function, we added a conditional statement that checks whether the input `x` is greater than 5. If it is, the function returns the string “Greater than 5”. Otherwise, it returns “Less than or equal to 5”. This allows us to get some useful output from our function based on the input provided!
Remember that they can be incredibly powerful tools for simplifying your code and making it more efficient, so don’t hesitate to use them whenever possible!