Add function code

returnvalue · returnvalue · commit a553d1137b39 · 2020-07-29T14:51:58.000-04:00
diff --git a/README.md b/README.md
@@ -13,4 +13,5 @@ repository breaks up the code into individual .py files, and the full tutorial f
 6. [Python If Statements](https://vegibit.com/python-if-statements/)
 7. [Python While And For Loops](https://vegibit.com/python-while-and-for-loops/)
 8. [Python Recursion Examples](https://vegibit.com/python-recursion-examples/)
-9. [Python Comprehension Tutorial](https://vegibit.com/python-comprehension-tutorial/)
+9. [Python Comprehension Tutorial](https://vegibit.com/python-comprehension-tutorial/)
+10. [Python Function Tutorial](https://vegibit.com/python-function-tutorial/)
diff --git a/function.py b/function.py
@@ -0,0 +1,230 @@
+# A function is a block of code which only runs when it is called. You can pass data, known
+# as parameters, into a function. A function can return data as a result.
+
+# Define a Python Function
+def hello_world():
+    print('Hello World!')
+
+
+# call a function
+hello_world()
+# Hello World!
+
+
+# Passing a single argument
+def hello_friend(friend):
+    print(f'Hello, {friend}!')
+
+
+# call function passing in argument
+hello_friend('Mosely')
+hello_friend('Winnie')
+# Hello, Mosely!
+# Hello, Winnie!
+
+
+# Passing a list as an argument
+def hello_friends(names):
+    for name in names:
+        message = f'Hello, {name}!'
+        print(message)
+
+
+# call function passing in a list
+hello_friends(['Winnie', 'Mosely', 'Bella', 'Mugsy'])
+# Hello, Winnie!
+# Hello, Mosely!
+# Hello, Bella!
+# Hello, Mugsy!
+
+
+# Use a function to modify a list
+def hello_friends(names):
+    while names:
+        name = names.pop()
+        message = f'Hello, {name}!'
+        print(message)
+
+
+original = ['Winnie', 'Mosely', 'Bella', 'Mugsy']
+print(original)
+# ['Winnie', 'Mosely', 'Bella', 'Mugsy']
+
+hello_friends(original)
+# Hello, Mugsy!
+# Hello, Bella!
+# Hello, Mosely!
+# Hello, Winnie!
+
+print(original)
+# []
+
+
+#  Prevent a function from modifying a list
+def hello_friends(names):
+    while names:
+        name = names.pop()
+        message = f'Hello, {name}!'
+        print(message)
+
+
+original = ['Winnie', 'Mosely', 'Bella', 'Mugsy']
+copy = original[:]
+print(original)
+# ['Winnie', 'Mosely', 'Bella', 'Mugsy']
+
+hello_friends(copy)
+# Hello, Mugsy!
+# Hello, Bella!
+# Hello, Mosely!
+# Hello, Winnie!
+
+print(original)
+# ['Winnie', 'Mosely', 'Bella', 'Mugsy']
+
+
+# Using positional arguments
+def describe_car(make, model):
+    print(f'The {make} {model} is a neat vehicle')
+
+
+describe_car('Subaru', 'WRX')
+# The Subaru WRX is a neat vehicle
+
+describe_car('Tesla', 'Model 3')
+# The Tesla Model 3 is a neat vehicle
+
+describe_car('Tesla', 'Cybertruck')
+# The Tesla Cybertruck is a neat vehicle
+
+
+# Using keyword arguments
+def describe_car(make, model):
+    print(f'The {make} {model} is a neat vehicle')
+
+
+describe_car('Subaru', 'WRX')
+# The Subaru WRX is a neat vehicle
+
+describe_car(make='Tesla', model='Model 3')
+# The Tesla Model 3 is a neat vehicle
+
+describe_car(model='Corvette', make='Chevy')
+# The Chevy Corvette is a neat vehicle
+
+
+# Using a default value
+def describe_car(make, model='WRX'):
+    print(f'The {make} {model} is a neat vehicle')
+
+
+describe_car('Subaru')
+# The Subaru WRX is a neat vehicle
+
+
+# Using None to make an argument optional
+def describe_car(make, model=None):
+    if model:
+        print(f'The {make} {model} is a neat vehicle')
+    else:
+        print(f'The {make} is a neat vehicle')
+
+
+describe_car('Subaru')
+# The Subaru is a neat vehicle
+
+describe_car(model='Corvette', make='Chevy')
+# The Chevy Corvette is a neat vehicle
+
+
+# Function with an arbitrary number of arguments
+def make_a_sandwich(type, *veggies):
+    print(f'\nMaking a {type} Sandwich.')
+    print('It has these veggies:')
+    for veggie in veggies:
+        print(f'- {veggie}')
+
+
+make_a_sandwich('Ham', 'Onions')
+# Making a Ham Sandwich.
+# It has these veggies:
+# - Onions
+
+make_a_sandwich('Roast Beef', 'Lettuce', 'Tomato')
+# Making a Roast Beef Sandwich.
+# It has these veggies:
+# - Lettuce
+# - Tomato
+
+make_a_sandwich('Turkey', 'Lettuce', 'Tomato', 'Peppers')
+# Making a Turkey Sandwich.
+# It has these veggies:
+# - Lettuce
+# - Tomato
+# - Peppers
+
+
+# Collecting an arbitrary number of keyword arguments
+def make_a_sandwich(type, **veggies):
+    print(f'\nMaking a {type} Sandwich.')
+    print('It has these veggies:')
+    for veggie in veggies:
+        print(f'- {veggies[veggie]}')
+
+
+make_a_sandwich('Ham', one='Onions')
+# Making a Ham Sandwich.
+# It has these veggies:
+# - Onions
+
+make_a_sandwich('Roast Beef', one='Onions', two='Peppers')
+# Making a Roast Beef Sandwich.
+# It has these veggies:
+# - Onions
+# - Peppers
+
+make_a_sandwich('Turkey', one='Olives', two='Spinach', three='Cucumbers')
+# Making a Turkey Sandwich.
+# It has these veggies:
+# - Olives
+# - Spinach
+# - Cucumbers
+
+
+# Returning a single value
+def get_full_name(first, last):
+    full_name = f'{first} {last}'
+    return full_name.title()
+
+
+comedian = get_full_name('ricky', 'gervais')
+print(comedian)
+# Ricky Gervais
+
+
+# Returning a dictionary
+def build_house(type, bedrooms):
+    house = {'type': type, 'bedrooms': bedrooms}
+    return house
+
+
+house = build_house('Colonial', 3)
+print(house)
+# {'type': 'Colonial', 'bedrooms': 3}
+
+
+# Returning a dictionary with optional values
+def build_house(type, bedrooms, pool=None):
+    house = {'type': type, 'bedrooms': bedrooms}
+    if pool:
+        house['pool'] = pool
+    return house
+
+
+house = build_house('Colonial', 3)
+print(house)
+# {'type': 'Colonial', 'bedrooms': 3}
+
+house = build_house('Colonial', 2, 'No')
+print(house)
+# {'type': 'Colonial', 'bedrooms': 2, 'pool': 'No'}
