tqdm - Python的一个快速，可扩展的进度条
tqdm - Python的一个快速，可扩展的进度条。
Instantly make your loops show a smart progress meter - just wrap any iterable with "tqdm(iterable)", and you're done!
from tqdm import tqdm for i in tqdm(range(9)): ...Here's what the output looks like:
76%|████████████████████ | 7641/10000 [00:34<00:10, 222.22 it/s]
trange(N) can be also used as a convenient shortcut for tqdm(xrange(N)).
Overhead is low -- about 60ns per iteration (80ns with gui=True). By comparison, the well established ProgressBar has an 800ns/iter overhead.
In addition to its low overhead, tqdm uses smart algorithms to predict the remaining time and to skip unnecessary iteration displays, which allows for a negligible overhead in most cases.
tqdm works on any platform (Linux, Windows, Mac, FreeBSD, Solaris/SunOS), in any console or in a GUI, and is also friendly with IPython/Jupyter notebooks.
tqdm does not require any library (not even curses!) to run, just a vanilla Python interpreter will do.
Table of contents
Installation
Latest pypi stable release
pip install tqdmLatest development release on github
Pull and install in the current directory:
pip install -e git+https://github.com/tqdm/tqdm.git@master#egg=tqdmUsage
tqdm is very versatile and can be used in a number of ways. The two main ones are given below.
Iterable-based
Wrap tqdm() around any iterable:
for char in tqdm(["a", "b", "c", "d"]): print chartrange(i) is a special optimised instance of tqdm(range(i)):
for i in trange(100): passInstantiation outside of the loop allows for manual control over tqdm():
pbar = tqdm(["a", "b", "c", "d"]) for char in pbar: pbar.set_description("Processing %s" % char)Manual
Manual control on tqdm() updates by using a with statement:
with tqdm(total=100) as pbar: for i in range(10): pbar.update(10)If the optional variable total (or an iterable with len()) is provided, predictive stats are displayed.
with is also optional (you can just assign tqdm() to a variable, but in this case don't forget to close() at the end:
pbar = tqdm(total=100) for i in range(10): pbar.update(10) pbar.close()Documentation
class tqdm(object): """ Decorate an iterable object, returning an iterator which acts exactly like the original iterable, but prints a dynamically updating progressbar every time a value is requested. """ def __init__(self, iterable=None, desc=None, total=None, leave=False, file=sys.stderr, ncols=None, mininterval=0.1, maxinterval=10.0, miniters=None, ascii=None, disable=False, unit='it', unit_scale=False, dynamic_ncols=False, smoothing=0.3, nested=False, bar_format=None, initial=0, gui=False):Parameters
-
- iterable : iterable, optional
-
Iterable to decorate with a progressbar. Leave blank [default: None] to manually manage the updates.
-
- desc : str, optional
-
Prefix for the progressbar [default: None].
-
- total : int, optional
-
The number of expected iterations. If not given, len(iterable) is used if possible. As a last resort, only basic progress statistics are displayed (no ETA, no progressbar). If gui is True and this parameter needs subsequent updating, specify an initial arbitrary large positive integer, e.g. int(9e9).
-
- leave : bool, optional
-
If [default: False], removes all traces of the progressbar upon termination of iteration.
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- file : io.TextIOWrapper or io.StringIO, optional
-
Specifies where to output the progress messages [default: sys.stderr]. Uses file.write(str) and file.flush() methods.
-
- ncols : int, optional
-
The width of the entire output message. If specified, dynamically resizes the progressbar to stay within this bound. If [default: None], attempts to use environment width. The fallback is a meter width of 10 and no limit for the counter and statistics. If 0, will not print any meter (only stats).
-
- mininterval : float, optional
-
Minimum progress update interval, in seconds [default: 0.1].
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- maxinterval : float, optional
-
Maximum progress update interval, in seconds [default: 10.0].
-
- miniters : int, optional
-
Minimum progress update interval, in iterations [default: None]. If specified, will set mininterval to 0.
-
- ascii : bool, optional
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If [default: None] or false, use unicode (smooth blocks) to fill the meter. The fallback is to use ASCII characters 1-9 #.
-
- disable : bool
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Whether to disable the entire progressbar wrapper [default: False].
-
- unit : str, optional
-
String that will be used to define the unit of each iteration [default: 'it'].
-
- unit_scale : bool, optional
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If set, the number of iterations will be reduced/scaled automatically and a metric prefix following the International System of Units standard will be added (kilo, mega, etc.) [default: False].
-
- dynamic_ncols : bool, optional
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If set, constantly alters ncols to the environment (allowing for window resizes) [default: False].
-
- smoothing : float
-
Exponential moving average smoothing factor for speed estimates (ignored in GUI mode). Ranges from 0 (average speed) to 1 (current/instantaneous speed) [default: 0.3].
-
- nested : bool, optional
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Whether this iterable is nested in another one also managed by tqdm [default: False]. Allows display of multiple, nested progress bars.
-
- bar_format : str, optional
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Specify a custom bar string formatting. May impact performance. [default: '{l_bar}{bar}{r_bar}'], where l_bar is '{desc}{percentage:3.0f}%|' and r_bar is '| {n_fmt}/{total_fmt} [{elapsed_str}<{remaining_str}, {rate_fmt}]'. Possible vars: bar, n, n_fmt, total, total_fmt, percentage, rate, rate_fmt, elapsed, remaining, l_bar, r_bar, desc.
-
- initial : int, optional
-
The initial counter value. Useful when restarting a progress bar [default: 0].
Returns
- out : decorated iterator.
def update(self, n=1): """ Manually update the progress bar, useful for streams such as reading files. E.g.: >>> t = tqdm(total=filesize) # Initialise >>> for current_buffer in stream: ... ... ... t.update(len(current_buffer)) >>> t.close() The last line is highly recommended, but possibly not necessary if `t.update()` will be called in such a way that `filesize` will be exactly reached and printed. Parameters ---------- n : int Increment to add to the internal counter of iterations [default: 1]. """ def close(self): """ Cleanup and (if leave=False) close the progressbar. """ def trange(*args, **kwargs): """ A shortcut for tqdm(xrange(*args), **kwargs). On Python3+ range is used instead of xrange. """ class tqdm_gui(tqdm): """ Experimental GUI version of tqdm! """ def tgrange(*args, **kwargs): """ Experimental GUI version of trange! """Examples and Advanced Usage
See the examples folder or import the module and run help().
Hooks and callbacks
tqdm can easily support callbacks/hooks and manual updates. Here's an example with urllib:
urllib.urlretrieve documentation
[...]If present, the hook function will be called onceon establishment of the network connection and once after each block readthereafter. The hook will be passed three arguments; a count of blockstransferred so far, a block size in bytes, and the total size of the file.[...]
import urllib from tqdm import tqdm def my_hook(t): """ Wraps tqdm instance. Don't forget to close() or __exit__() the tqdm instance once you're done with it (easiest using `with` syntax). Example ------- >>> with tqdm(...) as t: ... reporthook = my_hook(t) ... urllib.urlretrieve(..., reporthook=reporthook) """ last_b = [0] def inner(b=1, bsize=1, tsize=None): """ b : int, optional Number of blocks just transferred [default: 1]. bsize : int, optional Size of each block (in tqdm units) [default: 1]. tsize : int, optional Total size (in tqdm units). If [default: None] remains unchanged. """ if tsize is not None: t.total = tsize t.update((b - last_b[0]) * bsize) last_b[0] = b return inner eg_link = 'http://www.doc.ic.ac.uk/~cod11/matryoshka.zip' with tqdm(unit='B', unit_scale=True, leave=True, miniters=1, desc=eg_link.split('/')[-1]) as t: # all optional kwargs urllib.urlretrieve(eg_link, filename='/dev/null', reporthook=my_hook(t), data=None)It is recommend to use miniters=1 whenever there is potentially large differences in iteration speed (e.g. downloading a file over a patchy connection).
Pandas Integration
Due to popular demand we've added support for pandas -- here's an example for DataFrameGroupBy.progress_apply:
import pandas as pd import numpy as np from tqdm import tqdm, tqdm_pandas df = pd.DataFrame(np.random.randint(0, 100, (100000, 6))) # Create and register a new `tqdm` instance with `pandas` # (can use tqdm_gui, optional kwargs, etc.) tqdm_pandas(tqdm()) # Now you can use `progress_apply` instead of `apply` df.groupby(0).progress_apply(lambda x: x**2)In case you're interested in how this works (and how to modify it for your own callbacks), see the examples folder or import the module and run help().
Nested progress bars
tqdm supports nested progress bars, you just need to specify the nested=True argument for all tqdm instantiations except the outermost bar. Here's an example:
from tqdm import trange from time import sleep for i in trange(10, desc='1st loop', leave=True): for j in trange(5, desc='2nd loop', leave=True, nested=True): for k in trange(100, desc='3nd loop', leave=True, nested=True): sleep(0.01)On Windows colorama will be used if available to produce a beautiful nested display.
How to make a good progress bar
A good progress bar is a useful progress bar. To be useful, tqdm displays statistics and uses smart algorithms to predict and automagically adapt to a variety of use cases with no or minimal configuration.
However, there is one thing that tqdm cannot do: choose a pertinent progress indicator. To display a useful progress bar, it is very important that you ensure that you supply tqdm with the most pertinent progress indicator, which will reflect most accurately the current state of your program. Usually, a good way is to preprocess quickly to first evaluate the total amount of work to do before beginning the real processing.
To illustrate the importance of a good progress indicator, let's take the following example: you want to walk through all files of a directory and process their contents to do your biddings.
Here is a basic program to do that:
import os from tqdm import tqdm, trange from time import sleep def dosomething(buf): """Do something with the content of a file""" sleep(0.01) pass def walkdir(folder): """Walk through each files in a directory""" for dirpath, dirs, files in os.walk(folder): for filename in files: yield os.path.abspath(os.path.join(dirpath, filename)) def process_content_no_progress(inputpath, blocksize=1024): for filepath in walkdir(inputpath): with open(filepath, 'rb') as fh: buf = 1 while (buf): buf = fh.read(blocksize) dosomething(buf)process_content_no_progress() does the job alright, but it does not show any information about the current progress, nor how long it will take.
To quickly fix that using tqdm, we can use this naive approach:
def process_content_with_progress1(inputpath, blocksize=1024): for filepath in tqdm(walkdir(inputpath), leave=True): with open(filepath, 'rb') as fh: buf = 1 while (buf): buf = fh.read(blocksize) dosomething(buf)process_content_with_progress1() will load tqdm(), but since the iterator does not provide any length (os.walkdir() does not have a __len__() method for the total files count), there is only an indication of the current and past program state, no prediction:
4it [00:03, 2.79it/s]
The way to get predictive information is to know the total amount of work to be done. Since os.walkdir() cannot give us this information, we need to precompute this by ourselves:
def process_content_with_progress2(inputpath, blocksize=1024): # Preprocess the total files count filecounter = 0 for dirpath, dirs, files in tqdm(os.walk(inputpath)): for filename in files: filecounter += 1 for filepath in tqdm(walkdir(inputpath), total=filecounter, leave=True): with open(filepath, 'rb') as fh: buf = 1 while (buf): buf = fh.read(blocksize) dosomething(buf)process_content_with_progress2() is better than the naive approach because now we have predictive information:
50%|██████████████████████ | 2/4 [00:00<00:00, 4.06it/s]
However, the progress is not smooth: it increments in steps, 1 step being 1 file processed. The problem is that we do not just walk through files tree, but we process the files contents. Thus, if we stumble on one big fat file, it will take a huge deal more time to process than other smaller files, but the progress bar cannot know that, because we only supplied the files count, so it considers that every element is of equal processing weight.
To fix this, we should use another indicator than the files count: the total sum of all files sizes. This would be more pertinent since the data we process is the files' content, so there is a direct relation between size and content.
Below we implement this approach using a manually updated tqdm bar, where tqdm will work on size, while the for loop works on files paths:
def process_content_with_progress3(inputpath, blocksize=1024): # Preprocess the total files sizes sizecounter = 0 for dirpath, dirs, files in tqdm(os.walk(inputpath)): for filename in files: fullpath = os.path.abspath(os.path.join(dirpath, filename)) sizecounter += os.stat(fullpath).st_size # Load tqdm with size counter instead of files counter with tqdm(total=sizecounter, leave=True, unit='B', unit_scale=True) as pbar: for dirpath, dirs, files in os.walk(inputpath): for filename in files: fullpath = os.path.abspath(os.path.join(dirpath, filename)) with open(fullpath, 'rb') as fh: buf = 1 while (buf): buf = fh.read(blocksize) dosomething(buf) if buf: pbar.update(len(buf))And here is the result: a much smoother progress bar with meaningful predicted time and statistics:
47%|██████████████████▍ | 152K/321K [00:03<00:03, 46.2KB/s]
Contributions
To run the testing suite please make sure tox (https://testrun.org/tox/latest/) is installed, then type tox from the command line.
Where tox is unavailable, a Makefile-like setup is provided with the following command:
$ python setup.py make alltestsTo see all options, run:
$ python setup.py makeSee the CONTRIBUTE file for more information.
License
Authors
- Casper da Costa-Luis (casperdcl)
- Stephen Larroque (lrq3000)
- Hadrien Mary (hadim)
- Noam Yorav-Raphael (noamraph)*
- Ivan Ivanov (obiwanus)
- Mikhail Korobov (kmike)
* Original author