As developers, we often need to present information in a user-friendly way, especially when the computation takes a long time to complete. One of the common ways to indicate the progress of a long-running computation is by using progress bars. A progress bar is a graphical representation that indicates the progress of a task by filling or emptying a bar based on the completion status.
In Python, we can easily create progress bars using the tqdm library. tqdm is a Python library that provides a progress bar displaying the progress of a loop. In this article, we will explore how to create progress bars using tqdm in Python.
Installing tqdm Library
To install the tqdm library, simply run the following command in your command prompt or terminal:
pip install tqdm
Once installed, you can import it into your Python code:
from tqdm import tqdm
Creating Progress Bars
To create a progress bar, you need to use the tqdm function with an iterable. For example, let's create a simple progress bar for a loop that iterates over a list:
my_list = ['apple', 'banana', 'cherry']
for item in tqdm(my_list):
# Do some computation here
In the above code, we imported the tqdm function from the tqdm library and used it in a loop that iterates over a list of items. The progress bar will be automatically displayed in the console, indicating the progress of the loop.
You can also specify the total number of iterations in the loop using the total parameter. This is useful when working with nested loops:
total_items = 100
for i in tqdm(range(total_items), desc='Outer loop'):
for j in tqdm(range(total_items), desc='Inner loop', leave=False):
# Do some computation here
In the above code, we used the tqdm function for both the outer and inner loops. We specified the total number of items in each loop using the range function. The leave parameter is used to indicate whether the progress bar should leave the last line intact or clear it.
Customizing Progress Bars
You can customize the appearance of the progress bar by passing arguments to the tqdm function. For example, the position parameter is used to specify the position of the progress bar in the console:
for item in tqdm(my_list, position=0):
# Do some computation here
The desc parameter is used to specify the description of the progress bar:
for item in tqdm(my_list, desc='Progress', position=0):
# Do some computation here
The colour parameter is used to specify the colour of the progress bar:
for item in tqdm(my_list, desc='Progress', position=0, colour='blue'):
# Do some computation here
Other parameters that can be passed to the tqdm function include:
- miniters: the minimum number of iterations before updating the progress bar.
- dynamic_ncols: whether to dynamically adjust the width of the progress bar based on the console width.
- unit: the unit of measurement to be displayed with the progress bar.
- smoothing: the rate of smoothing to apply to the progress bar.
Conclusion
In this article, we explored how to create progress bars using the tqdm library in Python. We learned how to install the tqdm library, create progress bars for loops, customize the appearance of progress bars, and more. By using progress bars, we can provide a better user experience and increase the efficiency of computation.
Sure! Let's go over some additional details on the topics we covered.
Installing Tqdm Library
When installing the tqdm library, you can also specify the version you want. For example, if you want to install version 4.60.0, you can run:
pip install tqdm==4.60.0
Upgrading or downgrading the library is also possible:
pip install --upgrade tqdm
pip install tqdm==4.59.0
Creating Progress Bars
tqdm works with any iterable. It means you can also use it with generator expressions or custom iterators. Let's see an example:
my_generator = (i ** 2 for i in range(10))
for item in tqdm(my_generator):
# Do some computation here
The progress bar will automatically adjust its size based on the number of items in the iterable.
Customizing Progress Bars
You can customize the total width of the progress bar using the ncols parameter. By default, the width is set to the console size, but you can provide a fixed value:
for item in tqdm(my_list, desc='Progress', position=0, ncols=50):
# Do some computation here
The progress bar will take up to 50 characters in the console.
The leave parameter, as we mentioned before, indicates whether the last line of the progress bar should be erased or not. If you set it to False, the final message will remain in the console:
for item in tqdm(my_list, leave=False):
# Do some computation here
tqdm.write('Done!')
The tqdm.write function prints a message that will be kept in the console even after the loop exits.
The smoothing parameter controls the rate of smoothing applied to the progress bar. Setting it to True enables exponential averaging to smooth out the progress bar's motion:
for item in tqdm(my_list, smoothing=True):
# Do some computation here
The smoothing will make the progress bar move more slowly and stay smoother.
Conclusion
tqdm is a versatile library with options to adapt to almost every need. With its ease of use, it can save you considerable time in adding progress bars to existing code and keeping track of long processes. The library is also regularly updated, and there are active contributors maintaining it. So, if you need to include progress bars in your Python code, give tqdm a try!
Popular questions
Sure, here are 5 questions and answers related to the article:
- What is tqdm?
tqdm is a Python library that provides a progress bar displaying the progress of a loop.
- How do you install tqdm?
You can install the tqdm library using pip. Open your command prompt or terminal and run the command 'pip install tqdm'. Make sure you have pip installed before running the command.
- How do you create a progress bar for a loop that iterates over a list?
To create a progress bar for a loop that iterates over a list, use the tqdm function with the list as the parameter. Here's an example:
my_list = ['apple', 'banana', 'cherry']
for item in tqdm(my_list):
# Do some computation here
- What is the 'leave' parameter used for in tqdm?
The 'leave' parameter is used to indicate whether the progress bar should leave the last line intact or clear it. By default, it is set to True, which means the last line will be cleared. If you set it to False, the last line will be kept in the console.
- Can you customize the appearance of the progress bar in tqdm?
Yes, you can customize the appearance of the progress bar in tqdm by passing arguments to the tqdm function, such as 'desc' to specify the description of the progress bar, 'position' to specify the position of the progress bar, 'colour' to specify the colour of the progress bar, and more. Additionally, you can customize the total width of the progress bar using the 'ncols' parameter and control the rate of smoothing using the 'smoothing' parameter.
Tag
Progression
