Cheat Sheet English

MM Python cheat sheet

Base

Output

Base form

print()

Example

print("Hello World!") => Hello World!

Explanation

Send the desired output to the console.

Input

Base form

input()

Example

input("Enter your name: ") => Enter your name: _ (Waiting for interactive input)

Explanation

Allows receiving input from the console user for all sorts of operations.

Casting

Base form

int() / str() / float()

Example

int("1") => 1
str(1) => "1"
float(1) => 1.0

Explanation

Conversion from string to integer, integer/float to string or integer to float.

Strings

Slicing

Base form

"string"[START:END:STEP]

Examples

"ABCD"[1:3] => BC
"ABCDEFG"[1:-3] => BCD
"ABCDEFGHIJKLM"[:4:-1] => MLKJIHGF

Explanation

Some string slicing techniques. works for lists, tuples and sets aswell
[START::] Represents the pointer location to begin with, negative numbers are counted from the end.
[:END:] Represents the pointer location to end with, negative numbers are counted from the end.
[::STEP] Represents the number of places for a step, negative numbers are reversing the order.

String casing manipulation

Base form

"string".upper() / "string".lower()

Examples

"Python Course".upper() => PYTHON COURSE
"Python Course".lower() => python course
"wEIRD Case"[0].upper() + "wEIRD Case"[1:].lower() => Weird case

Explanation

Changing the entire string into either UPPERCASE or lowercase depending on the respective function.

Counting inside string

Base form

"string".count("")

Examples

"Hello World!".count("!") => 1
"This is an example".count("is") => 2
"wEIrD CAse StrING".lower().count("s") => 2 #Function chaining to find an occurence inside mixed-case string

Explanation

Count occurences of substring inside another string.

other methods for strings

Medthods for strings

Conditions (if statements)

Boolean (bool) values

Base form

False\ True

Examples

number1 > \ < \ >= \ <=\ == \ != number2
item in list\ string
item not in list\ string
True and False == False
True and True == True
True or False == True

Explanation

Boolean values can have 2 states, either True or False. They can be used to create conditions.

Conditions

Base form

if bool:
    option1
elif bool:
    option2
else:
    default_option

Examples

# condition1\condition2 are Boolean

if condition1:
    this will run only if condition1 is True
elif condition2:
    this will run only if condition1 is False AND condition2 is True
else:
    this will run if only if condition1 AND condition2 are False

Explanation

Conditions allow running certain code under certain conditions.

Lists

Adding\Removing an object from a list

Base form

list.append() list.pop()

Examples

ls = ["Tony", "Ana", "Dan", "Dvora"]
ls.append("Hanna")
print(ls)

["Tony", "Ana", "Dan", "Dvora", "Hanna"]

ls = ["Tony", "Ana", "Dan", "Dvora"]
index = ls.index("Ana")
ls.pop(index)
print(ls)

["Tony", "Dan", "Dvora"]

Explanation

.append(object) adds the object you put in it to the end of the list as is shown.
.pop(int) pops the item at the specified index, can be used with .index() to remove a specific item from the list

Sorting a list

Base form

list.sort() sorted(list)

Examples

ls = [4,2,5,1,3]
ls.sort()
print(ls)

[5,4,3,2,1]

ls = [4,2,5,1,3]
ls2 = sorted(ls)
print(ls2)
print(ls)

[5,4,3,2,1]
[4,2,5,1,3]

Explanation

When you dont need the original list order use sort(). if you do need it, use sorted() and put the sorted list in a new variable

SUM/MIN/MAX values from a list

Base form

sum(list) min(list) max(list)

Examples

ls = [13,4,2,51,-1,3]
max_number = max(ls)
min_number = min(ls)
sum_of_list = sum(ls)
print(max_number)
print(min_number)
print(sum_of_list)

51
-1
72

Explanation

these are 3 useful functions you can use on a list

other methods for lists

Medthods for lists