pywebcat package

Submodules

pywebcat.cli module

pywebcat.cli.dir_path(path: str)

Utility function for argparse to check existence of a passed directory.

Parameters:path (str) – Absolute path to local directory.

pywebcat.cli.main()

Command line function for saving frames of webCAT videos.

pywebcat.cli.parse_args()

pywebcat.utils module

class pywebcat.utils.TqdmUpTo(iterable=None, desc=None, total=None, leave=True, file=None, 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, bar_format=None, initial=0, position=None, postfix=None, unit_divisor=1000, write_bytes=None, lock_args=None, nrows=None, gui=False, **kwargs)

Bases: tqdm.std.tqdm

Utility class for displaying a progress bar.

download_url(self, fout=None, verbose=1)

Download the video from the url.

Examples

>>> url = "http://webcat-video.axds.co/buxtoncoastalcam/raw/2019/2019_11/2019_11_13/buxtoncoastalcam.2019-11-13_1000.mp4"
>>> with TqdmUpTo(unit="B", unit_scale=True, unit_divisor=1024, miniters=1, desc=f"Saving to {fout}") as t:
>>>     urllib.request.urlretrieve(self.fin, fout, reporthook=t.update_to)
...
Saving to buxtoncoastalcam.2019-11-13_1000.mp4:  0%|      | 44.1M/125M [00:08<00:16, 5.18MB/s]

update_to(b: int = 1, bsize: int = 1, tsize: int = None)

Progress bar udpate function.

Parameters:

• b (int, optional) – Number of blocks transferred so far, by default 1
• bsize (int, optional) – Size of each block (in tqdm units), by default 1
• tsize (int, optional) – Total size (in tqdm units), by default None

class pywebcat.utils.WebCAT

Bases: object

Utility class for viewing local or remote webcat videos.

url

url to the .mp4 file.

name

Unique name based on url.

video

The cv2.VideoCapture object of the video file at url.

Type:cv2.VideoCapture

frames

Total number of frames in the video.

Type:int

fps

Frames per second in the video.

Type:int

width

Width of video frames in pixels.

Type:int

height

Height of video frames in pixels.

Type:int

download_url(self, fout=None, verbose=1)

Download the video from the url.

Examples

>>> from webcat_utils import VidRetriever
>>> url = "http://webcat-video.axds.co/buxtoncoastalcam/raw/2019/2019_11/2019_11_13/buxtoncoastalcam.2019-11-13_1000.mp4"
>>> vr = VidRetriever(url)
>>> vr.download_url()
...
Saving to buxtoncoastalcam.2019-11-13_1000.mp4:  0%|      | 44.1M/125M [00:08<00:16, 5.18MB/s]

download_url(fout: str = None, verbose: bool = True)

Download the video from the instance url.

Parameters:

• fout (str) – The file path to save the downloaded file to, e.g., ~/Downloads/download.mp4, by default None
• verbose ({True, False}, optional) – Display download progress bar, by default True

fps

frames

generate_url(station: str, year: int, month: int, day: int, time: int)

Generate WebCAT URLs and expressive name for files from user inputs.

Parameters:

• station (str) – Station name, e.g., “buxtoncoastalcam”.
• year (int) – Year of video, e.g., 2020.
• month (int) – Month (numerical) of video, e.g., 11.
• day (int) – Day of video, e.g., 17.
• time (int) – Time (24 hr) of video rounded to nearest 10 minutes, e.g., 0500 (5:00 am), 1300 (1:00 pm), 1330 (1:30pm).

height

plot_average_frame(step: int = 500)

Plot the average of every “step” frames in the video.

Parameters:step (int, optional) – The step between frames to average by, lower values result in a smoother average, by default 10.

Examples

>>> from webcat_utils import WebCAT
>>> wc.generate_url("buxtoncoastalcam", 2019, 11, 13, 1000)
>>> wc.plot_average_frame()
...
<matplotlib.subplot>

plot_frames(frames: list = [0])

Plot frames from the video, zero-based indexing.

Parameters:frames (list, optional) – List of the frames to display in a grid plot, by default [0].

Examples

>>> from webcat_utils import WebCAT
>>> wc.generate_url("buxtoncoastalcam", 2019, 11, 13, 1000)
>>> wc.plot_frames()
...
<matplotlib.subplots>

save_frames(delta_t: int = 10, fout_path: str = '', save_csv=True, verbose=False)

Download the video from the instance url.

Parameters:

• delta_t (int, optional) – A frame will be saved every delta_t seconds, by default 10.
• fout (str, optional) – Path to save frames and csv to, e.g., “~/Downloads/”.

width

Module contents