Functions Flashcards
what is a function ?
Functions are a convenient way to group our code into reusable blocks. A function contains a sequence of steps that can be performed repeatedly throughout a program without having to repeat the process of writing the same code again.
what is the - def - keyword
The def keyword indicates the beginning of a function (also known as a function header). The function header is followed by a name in snake_case format that describes the task the function performs
how to set up the start of a function
def function_name():
what is calling a function
The process of executing the code inside the body of a function is known as calling it (This is also known as “executing a function”)
calling a function will print the print statements
How do you call a function
To call our function, we must type out the function’s name followed by a pair of parentheses and no indentation:
function_name()
How is indentation in functions important for execution flow
In Python, the amount of whitespace tells the computer what is part of a function and what is not part of that function.
what are function paramaters
Function parameters allow our function to accept data as an input value. We list the parameters a function takes as input between the parentheses of a function ( ).
e.g
def my_function(single_parameter)
what is a paramater and what does it do ?
A paramater is treated like a variable
def trip_welcome(destination):
print(“Welcome to Tripcademy!”)
print(“Looks like you’re going to “ + destination + “ today.”)
for the paramater we are telling it that it should expect some data to pass through
what is an argument
The argument is the data that is passed in when we call the function, which is then assigned to the parameter name.
def trip_welcome(destination):
print(“Looks like you’re going to “ + destination + “ today.”)
trip_welcome(“Times Square”)
how do we actually use a parameter?
def trip_welcome(destination):
print(“Welcome to Tripcademy!”)
print(“Looks like you’re going to “ + destination + “ today.”)
Our parameter of destination is used by passing in an argument to the function when we call it.
trip_welcome(“Times Square”)
How to set mutiple paramaters
We can write a function that takes in more than one parameter by using commas:
def my_function(parameter1, parameter2, parameter3):
How to set an argument with mutiple paramaters
my_function(argument1, argument2)
what are Positional arguments
arguments that can be called by their position in the function definition.
How do you set keyword arguments
where we explicitly refer to what each argument is assigned to in the function call.
example:
calculate_taxi_price(rate=0.5, discount=10, miles_to_travel=100)
what are Keyword arguments
arguments that can be called by their name.
what are Default arguments
arguments that are given default values.
How do you set Default arguments
want to give our function parameters default values. We can provide a default value to a parameter by using the assignment operator (=).
This will happen in the function declaration rather than the function call.
example: default value will be 10
def calculate_taxi_price(miles_to_travel, rate, discount = 10):
calculate_taxi_price(10, 0.5)
What are user defined functions
User Defined Functions - functions that are written by users (like us!).
What are built in functions
functions that come built into Python for us to use
What does help() function do
will print a link to documentation for us and provide some details
What does the len() built in function do
To get the length of a string
length_of_destination = len(destination_name)
what does the max() and min() function do
max = Return the largest item in an iterable or the largest of two or more arguments.
min = returns the smallest value in a varible
what does the round() function do
values are rounded to the closest multiple of 10 to the power minus ndigits
How to set the scope of a variable inside and outside of a function
This function will print the favorite locations
favorite_locations = “Paris, Norway, Iceland”
def print_count_locations():
print(“There are 3 locations”)
def show_favorite_locations():
print(“Your favorite locations are: “ + favorite_locations)
print_count_locations()
show_favorite_locations()
what does the return keyword do
Functions can also return a value to the program so that this value can be modified or used later
allows us to reuse the value (in the form of a variable) throughout the rest of the program.
How to you return mutiple values
weather_data = [‘Sunny’, ‘Sunny’, ‘Cloudy’, ‘Raining’, ‘Snowing’]
def threeday_weather_report(weather):
first_day = “ Tomorrow the weather will be “ + weather[0]
second_day = “ The following day it will be “ + weather[1]
third_day = “ Two days from now it will be “ + weather[2]
return first_day, second_day, third_day
This function takes in a set of data in the form of a list for the upcoming week’s weather. We can get our returned function values by assigning them to variables when we call the function:
monday, tuesday, wednesday = threeday_weather_report(weather_data)
print(monday)
print(tuesday)
print(wednesday)
