A list of the standard library modules in Python3 I mainly use

random: This module provides functions for generating random numbers.
os: This module provides functions for interacting with the operating system.
sys: This module provides access to some variables used or maintained by the interpreter and to functions that interact strongly with the interpreter.
time: This module provides functions for working with time, including converting between representations, getting the current time, and sleeping.
re: This module provides regular expression matching operations.
zlib: This module provides functions for compression and decompression using the zlib library.
PIL (Python Imaging Library): This module provides functions for working with images.
requests: This module provides functions for making HTTP requests.
json: This module provides functions for working with JSON data.
itertools: This module provides functions for working with iterators.
urllib: This module provides functions for working with URLs.
math: This module provides mathematical functions.
base64: This module provides functions for encoding and decoding data in base64 representation.
ctypes: This module provides access to the C types library, which can be used to call functions in C libraries from Python.
collections: This module provides specialized container data types.
datetime: This module provides functions for working with dates and times.
logging: This module provides functions for logging messages.
glob: This module provides functions for finding files matching a specified pattern.
threading: This module provides functions for working with threads.
csv: This module provides functions for reading and writing CSV files.
functools: This module provides higher-order functions, which are functions that operate on or return other functions.
string: This module provides functions for working with strings.
subprocess: This module provides functions for working with subprocesses.
io: This module provides functions for working with input/output operations.
sysconfig: This module provides access to the configuration information used by the interpreter.
struct: This module provides functions for working with C-style structs.
argparse: This module provides functions for parsing command-line arguments.
decimal: This module provides support for fast correctly rounded decimal floating point arithmetic.
tempfile: This module provides functions for working with temporary files and directories.