Python Cheatsheet
Louie Aroy
Posted on November 8, 2019
Basic syntax examples for programmers who are starting to learn python.
Comments
# This is a single line comment
Numbers
# declare int
day = 18
# declare float
amount = 2.5
brothers_age = 30
my_age = 25
# math equation
age_gap = brothers_age - my_age
# output to console
print(age_gap)
"""
Result:
5
"""
Strings
# declare strings
first_name = "Louie"
last_name = "Aroy"
age = 25
print(first_name, last_name, age)
# concatenate
print(first_name + " " + last_name + " " + age)
"""
Result:
Louie Aroy 25
Louie Aroy 25
"""
List
# declare list
players = [25, 58, 66, 71, 87]
print (players[2])
"""
Result:
66
"""
# update list value
players[2] = 68
print (players)
Result:
[29, 58, 68, 71, 87]
# add variables to list
players.append(120)
print (players)
"""
Result:
[29, 58, 68, 71, 87, 120]
"""
# add multiple variable to list
players + [122, 123, 124]
print (players)
"""
Result:
[29, 58, 68, 71, 87, 120, 122, 123, 124]
"""
If Else
name = "Tommy"
if name is "Bucky":
print("Hey there Bucky")
elif name is "Lucy":
print("What up Lucy?")
elif name is "Sammy":
print("What up Slammy?")
else:
print("Please sign up for the site!")
"""
Result:
Please sign up for the site!
"""
For Loop
foods = ['bacon', 'tuna', 'ham', 'snausages', 'beef']
for food in foods:
print(food)
print(len(food))
"""
Result:
bacon
5
tuna
4
ham
3
snausages
9
beef
4
"""
Loop with Range
# loop 5 times
for x in range(5):
print("I'm awesome!")
# loop in 8 inclusive upto 12 exclusive
for x in range(8, 12):
print(x)
"""
Result:
I'm awesome!
I'm awesome!
I'm awesome!
I'm awesome!
I'm awesome!
8
9
10
11
"""
While loop
pimples = 5
while pimples < 10:
print(pimples)
pimples += 1
Functions
# declare a function
def bitcoin_to_usd(btc):
amount = btc * 527
print(amount)
# call a function
bitcoin_to_usd(3.85)
bitcoin_to_usd(1)
bitcoin_to_usd(13)
"""
Result:
2028.95
527
6851
"""
Return Values
def allowed_dating_age(my_age):
girls_age = my_age/2 + 7
return girls_age
buckys_limit = allowed_dating_age(27)
print("Bucky can date girls", buckys_limit, "or older")
creepy_joe_limit = allowed_dating_age(49)
print("Creepy Joe can date girls", creepy_joe_limit, "or older")
"""
Result:
Bucky can date girls 20.5 or older
Creepy Joe can date girls 31.5 or older
"""
Default Values for Arguments
def get_gender(sex='Unknown'):
if sex is 'm':
sex = "Male"
elif sex is 'f':
sex = 'Female'
print(sex)
get_gender('m')
get_gender('f')
get_gender()
"""
Result:
Male
Female
Unknown
"""
Keyword Arguments
def dumb_sentence(name='Bucky', action='ate', item='tuna'):
print(name, action, item)
dumb_sentence()
dumb_sentence("Sally", "laughs", "hard")
dumb_sentence(item="awesome", action="is")
"""
Result:
Bucky ate tuna
Sally laughs hard
Bucky is awesome
"""
Dictionary
# declare a dictionary
classmates = {
'Tony': 'cool but smells',
'Emma': 'sits behind me',
'Lucy': 'asks too many questions'
}
# loop through the dictionary
for k, v, in classmates.items():
print(k, v)
# output one dictionary value
print(classmates['Tony'])
"""
Result:
Lucy asks too many question
Tony cool but smells
Emma sits behind me
cool but smells
"""
Class
# create a class
class Person:
# on initialize
def __init__(self, name, age):
self.name = name
self.age = age
def introduce(self):
print("Hello my name is " + self.name + ", " + self.age + " years old.")
p1 = Person("John", 36)
p1.introduce()
"""
Result:
Hello my name is John, 36 years old.
"""
Inheritance
# inherit from above class
class Student(Person):
def studentIntro(self):
print("Hi classmates, my name is " + self.name + ", " + self.age + " years old.")
s1 = Student("Luigi", 15)
s1.introduce()
s1.studentIntro()
"""
Result:
Hello my name is Luigi, 15 years old.
Hi classmates, my name is Luigi, 15 years old.
"""
Modules
tuna.py
def fish()
print("I am a tuna feesh!")
main.py
import tuna
tuna.fish()
"""
Result:
I am a tuna feesh!
"""
Reference:
TheNewboston Python Tutorial
https://www.youtube.com/watch?v=HBxCHonP6Ro&list=PL6gx4Cwl9DGAcbMi1sH6oAMk4JHw91mC_
Syntax
https://www.w3schools.com/python/
Challenges
https://edabit.com/challenges/python3
💖 💪 🙅 🚩
Louie Aroy
Posted on November 8, 2019
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