Python 3 Cheat Sheet

Introduction to Python 3 Cheat Sheet

Python is a high-level programming language that was designed by Guido Van Rossum and developed by the Python software foundation in 1990. It has a paradigm of Object-oriented, imperative and procedural reflective. The parent company of python is a Python software foundation. It is used for web development, software development, and system scripting. now learn about the Python 3 cheat sheet

Importance of Python

• It can work with different platforms like MacOs, Windows and Linux.
• The Program in python 3 CheatSheet can be written in few lines in comparison with other programming languages.
• Python supports the procedural, object-oriented or functional way of programming.

How to install Python in your system?

• You can install python in your system free by going on the below link :
  https://www.python.org/
• Once Python is installed in your system, type the command python –version; it will reflect the python’s install version.

Some basics of Python 3 Cheat Sheet Programming

• Your first python program. Type the below command print (“what is your name?”) and press the enter it will generate the output what your name is?
• If you want to comment down something in python using the below procedure:
  #comment which you want to put.

Python 3 Cheat Sheet

Some of the Cheat Sheet of Python 3  is given below:

Storing variable

Print(“Hello World”), and the out will be Hello World.

Hello message with a variable

a = “Hello World”
Print(a)

How to deal with a list in the python3 Cheat sheet?

car = [‘Maruti’, ‘Audi’, ‘Ford’]

Getting the first item from the list

first_car = car[0]

Adding item to the list

car = [] append(‘Maruti’)

Slicing a list

car = [‘Maruti’, ‘Audi’, ‘Ford’] first_two = car[:2] list.append(val) → (add item at end)
list.extend (seq) → (add a sequence of an item at the end)
list.insert (idx,val) → (insert item at index)
list.remove (val) → (remove the first item with value val)
list.pop([idx]) → value (remove and return item at index idx)
list.sort (Sort the list)
list.reverse (Reverse the list)

Tuples

Tuples are similar to the list, but the only difference is that items on the list cannot be modified.
area = (1000, 2000)

Conditional operators

Dictionaries

Dictionaries stores the connections between the data. For Eg:

car = {'color': 'green', 'seats': 5}

User Input

Forgetting the data from the user, we use this syntax.

name = input("What's your name? ")

This will generate the output of — What’s your name?

Variable assignments

In this command, we can define the variables in the following way:

x=2.2+9+cos(y)
a=b=c=0 (assignment to same value)
y, z, r=2, -7.6, 0 (multiple assignments)
a, b=b, a (values swap)
a,*b=seq
*a, b=seq (item and list)
x+=3 (Increment → x=x+3)
x-=2 (decrement → x=x-2)
x=None (Constant value)
del x (remove name x)

Conversions

int (“19”) → 15
int (“3f”,19) → 72 (Can specify integer number base in 2nd parameter
int (15.56) → 15 (Truncate decimal part)
float(“-12.24e9”) → -12240000000.0
round(15.56,1)→ 15.6 (rounding to 1 decimal)
bytes ([71,6,90]) → b'G\x06Z'
list(“abc”) → [‘a’,’b’,’c’] set([“one”, “two”]) → {‘one’, ‘two’}

Spitted on white spaces → list of str, For example:

“I am back”.split() → [‘I’, ‘am’, ‘back’]

Spitted on seperator → list of str, For example:

“I, am, back”.split() → [‘I’, ‘am’, ‘back’]

Sequence container indexing

Suppose there is a list = [10, 20, 30, 40, 50] for this list indexing will be like this:

list[0] = 10
list[1] = 20
list[2] = 30
list[-1] = 50
list[-2] = 40
list[:-1] → [10,20,30,40] list[1:-1] → [20,30,40] list[::2] → [10,30,50] list[::-1] → [50,40,30,20,10] list[::-2] → [50,30,10
list[:] → [10,20,30,40,50] list[1:3] → [20,30] list[-3:-1] → [30,40] list[:3] → [10,20,30] list[3:] → [40,50]

Maths

sin(pi/4) → 707
cos(2*pi/3) → -0.4999
sqrt(81) → 9.0
log(e**2) → 2.0
ceil(12.5) → 13
floor(12.5) → 12

Display

Sep= “ “ (item seperator, default space)
end= “\n” (end of print, default new line)
file=sys.stdout (print to file, default standard output)

Generic operations on containers

len(c) → items count
min(c) → minimum
max(c) → maximum
Sum(c) → sum of the list
sorted(c) → list in sorted manner

How Python 3 Cheat Sheet is different from Version 2

Let us know how it differs from version 2.

• Division operator

For a case 7/5 or -7/5, then the output in Python 2 will be 1 and -2, respectively, but in python3 the output will be 1.4 and -1.4

• Unicode

In Python2 str type is ASCII, but in version 3, it is Unicode.

Conclusion

In the current era of Technology, python, 3 Cheat Sheet is a great way of learning a programming language. Many companies are now using it like Google, Facebook, YouTube. If you are a python3 developer, then you can earn up to 92000$ every year.

Recommended Articles

This has been a guide to Python 3 Cheat Sheet. Here we have discussed basic concept and command as well as free tips and tricks of it. You may also look at the following article to learn more –

1. Python File deadline
2. Python Stream
3. Python 3 Commands
4. Python 3 vs Python 2