How do I convert a password into asterisks while it is being entered?

There is getpass(), a function which hides the user input.

import getpass

password = getpass.getpass()
print(password)

If you're using Tkinter:

# For Python 2:
from Tkinter import Entry, Tk
# For Python 3
from tkinter import Entry, Tk

master = Tk()

Password = Entry(master, bd=5, width=20, show="*")
Password.pack()

master.mainloop()

In the shell, this is not possible. You can however write a function to store the entered text and report only a string of *'s when called. Kinda like this, which I did not write. I just Googled it.

If you want a solution that works on Windows/macOS/Linux and on Python 2 & 3, you can install the pwinput module (formerly called stdiomask):

pip install pwinput

Unlike getpass.getpass() (which is in the Python Standard Library), the pwinput module can display *** mask characters as you type. It is also cross-platform, while getpass is Linux and macOS only.

Example usage:

>>> pwinput.pwinput()
Password: *********
'swordfish'
>>> pwinput.pwinput(mask='X') # Change the mask character.
Password: XXXXXXXXX
'swordfish'
>>> pwinput.pwinput(prompt='PW: ', mask='*') # Change the prompt.
PW: *********
'swordfish'
>>> pwinput.pwinput(mask='') # Don't display anything.
Password:
'swordfish'

Unfortunately this module, like Python's built-in getpass module, doesn't work in IDLE or Jupyter Notebook.

More details at https://pypi.org/project/pwinput/