Python Quick Reviews
Nov. 2, 2020
Vuong Huynh
Comments
# This is a one-line Python comment - code blocks are so useful!
"""This type of comment is used to document the purpose of functions and classes."""
Declaration/Initialization
# Remember values, not variables, have data types.
# A variable can be reassigned to contain a different data type.
answer = 42
answer = "The answer is 42."
Data Types
boolean = True
number = 1.1
string = "Strings can be declared with single or double quotes."
list = ["Lists can have", 1, 2, 3, 4, "or more types together!"]
tuple = ("Tuples", "can have", "more than", 2, "elements!")
dictionary = {'one': 1, 'two': 2, 'three': 3}
variable_with_zero_data = None
Simple Logging
print("Printed!")
Conditionals
if cake == "delicious":
return "Yes please!"
elif cake == "okay":
return "I'll have a small piece."
else:
return "No, thank you."
Loops
for item in list:
print(item)
i = 1
while i < 5:
print(i)
i += 1
Functions
def divide(dividend, divisor):
quotient = dividend // divisor
remainder = dividend % divisor
return quotient, remainder
def calculate_stuff(x, y):
(q, r) = divide(x,y)
print(q, r)
print(divide(7, 2)) # (3, 1)
calculate_stuff(7,2) # 3 1
Classes
class Person():
def __init__(self, name, age):
self.name = name
self.age = age
def birthday(self):
self.age += 1
Python Practice
You can use this class to represent how classy someone or something is.
Classy
is interchangeable with fancy
. If you add fancy-looking items, you will increase your "classiness".
Create a function in Classy
that takes a string as input and adds it to the items
list.
Another method should calculate the classiness
value based on the items.
The following items have classiness points associated with them:
tophat = 2
bowtie = 4
monocle = 5
class Classy():
def __init__(self):
self.items = []
# Function getClassiness is to calculate classiness points of each item
def getClassiness(self):
classiness_item = 0
if len(self.items) > 0:
for item in self.items:
if item == "tophat" :
classiness_item += 2
elif item == "bowtie" :
classiness_item += 4
elif item == "monocle" :
classiness_item += 5
return classiness_item
# Create function addItem to append new items
def addItem(self, item):
self.items.append(item)
# Test cases
me = Classy()
# Should be 0
print(me.getClassiness())
me.addItem("tophat")
# Should be 2
print(me.getClassiness())
me.addItem("bowtie")
me.addItem("jacket")
me.addItem("monocle")
# Should be 11
print(me.getClassiness())
me.addItem("bowtie")
# Should be 15
print(me.getClassiness())
All sources from Udacity Course: Python Data Structures and Algorithms