This delays for 2.5 seconds:

import time
time.sleep(2.5)

Here is another example where something is run approximately once a minute:

import time
while True:
    print("This prints once a minute.")
    time.sleep(60) # Delay for 1 minute (60 seconds).

Use sleep() from the time module. It can take a float argument for sub-second resolution.

from time import sleep
sleep(0.1)  # Time in seconds

There are five methods which I know: time.sleep(), pygame.time.wait(), matplotlib's pyplot.pause(), .after(), and asyncio.sleep().

time.sleep() example (do not use if using tkinter):

import time
print('Hello')
time.sleep(5) # Number of seconds
print('Bye')

pygame.time.wait() example (not recommended if you are not using the pygame window, but you could exit the window instantly):

import pygame
# If you are going to use the time module
# don't do "from pygame import *"
pygame.init()
print('Hello')
pygame.time.wait(5000) # Milliseconds
print('Bye')

matplotlib's function pyplot.pause() example (not recommended if you are not using the graph, but you could exit the graph instantly):

import matplotlib
print('Hello')
matplotlib.pyplot.pause(5) # Seconds
print('Bye')

The .after() method (best with Tkinter):

import tkinter as tk # Tkinter for Python 2
root = tk.Tk()
print('Hello')
def ohhi():
    print('Oh, hi!')
root.after(5000, ohhi) # Milliseconds and then a function
print('Bye')

Finally, the asyncio.sleep() method (has to be in an async loop):

await asyncio.sleep(5)

If you would like to put a time delay in a Python script:

Use time.sleep or Event().wait like this:

from threading import Event
from time import sleep

delay_in_sec = 2

# Use time.sleep like this
sleep(delay_in_sec)         # Returns None
print(f'slept for {delay_in_sec} seconds')

# Or use Event().wait like this
Event().wait(delay_in_sec)  # Returns False
print(f'waited for {delay_in_sec} seconds')

However, if you want to delay the execution of a function do this:

Use threading.Timer like this:

from threading import Timer

delay_in_sec = 2

def hello(delay_in_sec):
    print(f'function called after {delay_in_sec} seconds')

t = Timer(delay_in_sec, hello, [delay_in_sec])  # Hello function will be called 2 seconds later with [delay_in_sec] as the *args parameter
t.start()  # Returns None
print("Started")

Outputs:

Started
function called after 2 seconds

Why use the later approach?

• It does not stop execution of the whole script (except for the function you pass it).
• After starting the timer you can also stop it by doing timer_obj.cancel().

asyncio.sleep

Notice in recent Python versions (Python 3.4 or higher) you can use asyncio.sleep. It's related to asynchronous programming and asyncio. Check out next example:

import asyncio
from datetime import datetime

@asyncio.coroutine
def countdown(iteration_name, countdown_sec):
    """
    Just count for some countdown_sec seconds and do nothing else
    """
    while countdown_sec > 0:
       print(f'{iteration_name} iterates: {countdown_sec} seconds')
       yield from asyncio.sleep(1)
       countdown_sec -= 1

loop = asyncio.get_event_loop()
tasks = [asyncio.ensure_future(countdown('First Count', 2)),
         asyncio.ensure_future(countdown('Second Count', 3))]

start_time = datetime.utcnow()

# Run both methods. How much time will both run...?
loop.run_until_complete(asyncio.wait(tasks))

loop.close()

print(f'total running time: {datetime.utcnow() - start_time}')

We may think it will "sleep" for 2 seconds for first method and then 3 seconds in the second method, a total of 5 seconds running time of this code. But it will print:

total_running_time: 0:00:03.01286

It is recommended to read asyncio official documentation for more details.

While everyone else has suggested the de facto time module, I thought I'd share a different method using matplotlib's pyplot function, pause.

An example

from matplotlib import pyplot as plt
plt.pause(5)    # Pauses the program for 5 seconds

Typically this is used to prevent the plot from disappearing as soon as it is plotted or to make crude animations.

This would save you an import if you already have matplotlib imported.

This is an easy example of a time delay:

import time

def delay(period='5'):
    # If the user enters nothing, it'll wait 5 seconds
    try:
        # If the user not enters a int, I'll just return ''
        time.sleep(period)
    except:
        return ''

Another, in Tkinter:

import tkinter

def tick():
    pass

root = Tk()
delay = 100 # Time in milliseconds
root.after(delay, tick)
root.mainloop()

You also can try this:

import time
# The time now
start = time.time() 
while time.time() - start < 10: # Run 1- seconds
    pass
# Do the job

Now the shell will not crash or not react.