Indentation
*Use four spaces for indentation
*Use hanging indentation for big expressions
*If you see a code already using tabs/space stick with tabs or respectively

Maximum line length
*79 characters in general
*72 characters for comments

Blank lines

• Top-level classes and functions are separated by two lines
• Method definitions inside classes should be separated by one blank line

WhiteSpaces in expressions
*Avoid whitespaces. Example: Should use- x=y instead of x= y

Imports
*Always import libraries at the start of your script.
*If you do many imports, you should make sure to state each import on a single line
Example: Use-
import os
import sys
Instead of
import os, sys
*You should take into account that there is an order that you need to respect when you're importing libraries. In general, you can follow this order:
Standard library imports.
Related third-party imports.
Local application/library specific imports.

Absolute imports>Relative imports

Ignore wildcard imports

Comments
*Block comments to explain code that is more complex or unfamiliar to others
*Block comments apply to code that follows
*Block comments are indented at the same level as the code. Each line of a block comment begins with the hashtag # and a single space

• You use inline comments on the same line of a statement, following the code itself. These comments also start with # and a single space.

• You write documentation strings or docstrings at the start of public modules, files, classes, and methods. These type of comments start with """ and end with """

Module level dunder
*A module-level dunder like (all, author, version) should be placed at the module main docstring and should be before all the import statements.

Naming Conventions
*Module-lowercase
*Class- CapWords
*Functions-lowercase
*Methods-lowercase
*Package-lowercase
*Contstans- UPPERCASE
*Type variables- CapWords

Reference for this post

(I basically made a summary. Didn't add two points i.e about the PEP-8 package and Source file encoding. Do read the link for better understanding)