Basic Python

Basic Components 🐍

Python follows basic order of operations when evaluating expressions, similar to PEMDAS for math.

Operator	Operation	Example	Evaluates to
**	Exponent	2**4	16
%	Modulus (remainder!)	5 % 2	1
//	Integer Division (floored)	11 // 2	5
/	Division	11 / 2	5.5
*	Multiplication	2 * 3	6
-	Subtraction	3 - 2	1
+	Addition	2 + 4	6

Data Types and Classifications 👩‍🏫

Using a single equals = is an assignment operator, where it assigns a value to a variable.

Using double equals == is a comparison operator, where it checks two values!

Flow Control 🌊🤽‍♀️

Tons of different ways to control execution of the program. Fundamental way in how programs work and look like magic ✨ Until you realize that whitespace is interpreted. Make sure you use four spaces instead of tabs, just as God intended.

# if, elif, and else control!!
ayyy = 'lmao'

# if statements check if a statement is true
if ayyy == 'lmao':
    print('👽👽👽')

# elif statments help  determine one of many possible clauses
elif len(ayyy) == 4:
    print('😂😂😂😂')

# can have have several elif, but skips any remaining elif after first True
elif len(ayyy) != 4:
    print('🤔🤔🤔')

# else statements is executed ONLY if the preceeding if is False (NOT REQUIRED!)
else:
    print('❌👽❌')

There are while loops which will check for a condition and keep executing until completed. Using break will exit the while loop early! Similarly, continue statements will jump back to the beginning of a while loop and evaluate the loop's condition.

# while loops will execute until a condition is met
count = 0

while count < 5:
    print('ayyy')
    count = count + 1
print('lmao')

name = ''
while name != 'your name':
    print('Please type your name')
    name = input()

# break statements exit the while loop's clause early, continue jump to start of while
name = ''
while True:
    print('Please type your name')
    name = input()
    if name != 'your name':
        continue
    print('What\'s the password?')
    pass = input()
    if pass = 'ayyylmao':
        break
print('Well done!')

Another loop is the for loop which can repeat an action a specific amount of times. When using range we can also specify start, stop, and steps.

ayyy = 'lmao'

# Print the var ayyy five times
for i in range(5):
    print(ayyy)

# Print the value of i between two values
for i in range(12, 15):
    print(i)

# Similar, only with a step!
for i in range(0, 10, 2):
    print(i)

Strings 🧵

We can take a string of any length and reference ANY part of it!

lmao = 'holy hell'

# Print first character of string lmao
print(lmao[0])

# Print last character of string lmao
print(lmao[-1])

# Print entire string backwards!
print(lmao[::-1])

# Split string on a delimeter, default is space
haha = lmao.split()
print(haha)

# Replace certain parts of a string
print(lmao.replace('h','')  # prints 'hoy he'

Lists 📜📜

ans = ['H', 'E', 'L', 'L', 'O']
print(''.join(ans))
# Will print HELLO

Comprehension

Search for a partial match in a list and add to another list. Super useful!

origList = ['big','bad','bigly']
subStr = 'ig'
filterList = [string for string in origList if subStr in string]

Tuples

Dictionaries 📚📚

Very similar to JSON. In fact, so close, it can be converted to JSON with minor worries!

# Create the dict type
lmao = {'one':1,'two':2}

# Add a new key to the dictionary
lmao['three'] = 3

# Loop over each pair of keys and values to access
for i, k in enumerate(lmao):
    print(i, k)

# Will print:
# one 1
# two 2
# three 3

User Inputs

Loops

from string import ascii_lowercase
for a in ascii_lowercase:
    for b in ascii_lowercase:
        print(a+b)

Arithmetic and Conditionals

Regex Matching

Convert bytes to IPv4

ipaddr = '.'.join(f'{c}' for c in line['ipAddress'])