How to show a progress bar in Python using tqdm
problem
Python doesn’t really support showing progress bars out of the box. But, we can use the tqdm library to show a pretty cool progress bar in the console. The progress bar can be formatted, e.g. to a specific color.
SOLUTION
The progress bar needs an Iterable collection to progress – iterate over. For our example, for simplicity we will create a list of numbers that the progress bar will iterate over and show the progress accordingly.
Let’s create a list of 20 numbers using list comprehension.
numbers = [x for x in range(20)]
To create a progress bar we simply call tqdm constructor and assign it to a local variable so we can control it after instantiation.
For example:
bar = tqdm(numbers) #pass the iterable in the constructor
Now, our progress bar is in the variable bar. We can iterate over this variable using a for loop and put a small delay on each iteration to avoid filling up the progress bar too quickly.
For the delay, we will use the sleep() function.
for n in bar:
sleep(0.1) #small delay in seconds
running complete code
from tqdm import tqdm
from time import sleep
numbers = [x for x in range(20)]
bar = tqdm(numbers)
for n in bar: #loop to fill up the progress bar
sleep(0.1)
output
Loading…
After loading – done
In this screenshot we can see the default format of the progress bar. It shows a percentage, then the bars, then 20/20 (20 items in numbers list), followed by some other data in square brackets.
Let’s customize it a bit.
Change the color
To change the color to blue, we do the following:
bar.colour="blue"
running complete code
from tqdm import tqdm
from time import sleep
numbers = [x for x in range(20)]
bar = tqdm(numbers)
bar.colour = "blue" #sets to Blue
for n in bar:
sleep(0.1)
output
Now, the progress bar is blue.
colors = ["BLACK", "RED", "GREEN", "YELLOW", "BLUE", "MAGENTA", "CYAN", "WHITE"]
If we put a color that is not in that list, e.g. purple:
from tqdm import tqdm
from time import sleep
numbers = [x for x in range(20)]
bar = tqdm(numbers)
bar.colour="PURPLE" # UNSUPPORTED colour
for n in bar:
sleep(0.1)
output - error
The progress bar will be empty and it will show the following error:
Adding a custom colour
To specify a custom colour, we can use a HEX code as follows:
from tqdm import tqdm
from time import sleep
numbers = [x for x in range(20)]
bar = tqdm(numbers)
bar.colour="#D4F3CE" # HEX code of custom colour
for n in bar:
sleep(0.1)
output
For fun - changing colours of progress bars
from tqdm import tqdm
from time import sleep
colors = ["#00ff00", "#D4F3CE", "BLACK", "RED", "GREEN", "YELLOW", "BLUE", "MAGENTA", "CYAN", "WHITE"]
numbers = [x for x in range(50)]
bar = tqdm(numbers)
i = 0
for char in bar:
sleep(0.1)
colour = colors[i % len(colors)] # pick next color repeadetly (first -> last -> repeat)
bar.colour = colour
i += 1
conclusion
In this post we saw how to use the tqdm package and show a progress bar in the console of our Python program.
Share it!
Ellion
Professional IT consultant, writer, programmer enthusiast interested in all sorts of coding.
Eats all cookies 🍪