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python - Python-OpenCV --F 函数错误--找不到正确的目录

问题描述

我试图在我的 OpenCV 代码上放置延时摄影，但似乎我在做一些不正确的事情，我不知道为什么会出现错误。我得到的错误是针对这一行：filename = f"{timelapse_img_dir}/{i}.jpg"我应该怎么做才能不出错？

这是我的 IDE 中出现的错误：

File "/Users/Dropbox/OpenCV/src/timelapse.py", line 34
    filename        = f"{timelapse}/{i}.jpg"
                                           ^
SyntaxError: invalid syntax
[Finished in 0.1s with exit code 1]
[shell_cmd: python -u "/Users/Dropbox/OpenCV/src/timelapse.py"]
[dir: /Users/Dropbox/OpenCV/src]
[path: /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin]

我的代码：

import os
import numpy as np
import cv2
import time
import datetime

from utils import CFEVideoConf, image_resize
import glob

cap = cv2.VideoCapture(0)


frames_per_seconds = 20
save_path='saved-media/timelapse.mp4'
config = CFEVideoConf(cap, filepath=save_path, res='720p')
out = cv2.VideoWriter(save_path, config.video_type, frames_per_seconds, config.dims)
timelapse_img_dir = '/Users/Dropbox/OpenCV/src/images/timelapse/'
seconds_duration = 20
seconds_between_shots = .25

if not os.path.exists(timelapse_img_dir):
    os.mkdir(timelapse_img_dir)

now = datetime.datetime.now()
finish_time = now + datetime.timedelta(seconds=seconds_duration)
i = 0
while datetime.datetime.now() < finish_time:
    '''
    Ensure that the current time is still less
    than the preset finish time
    '''
    ret, frame      = cap.read()
    # filename        = f"{timelapse_img_dir}/{i}.jpg"
    filename        = f"{timelapse_img_dir}/{i}.jpg"
    i               += 1
    cv2.imwrite(filename, frame)
    time.sleep(seconds_between_shots)
    if cv2.waitKey(20) & 0xFF == ord('q'):
        break


def images_to_video(out, image_dir, clear_images=True):
    image_list = glob.glob(f"{image_dir}/*.jpg")
    sorted_images = sorted(image_list, key=os.path.getmtime)
    for file in sorted_images:
        image_frame  = cv2.imread(file)
        out.write(image_frame)
    if clear_images:
        '''
        Remove stored timelapse images
        '''
        for file in image_list:
            os.remove(file)

images_to_video(out, timelapse_img_dir)
# When everything done, release the capture
cap.release()
out.release()
cv2.destroyAllWindows()

标签： pythonopencv

解决方案

我相信您使用的格式仅在 python 3.6“文字字符串插值”上受支持：

https://www.python.org/dev/peps/pep-0498/#raw-f-strings

filename  = f"{timelapse_img_dir}/{i}.jpg"

这里有 2 个其他选项取决于您使用的 python：

蟒蛇2.7：

filename = '%(timelapse_img_dir)s %(i)s' % locals()

蟒蛇 3+

filename = '{timelapse_img_dir} {i}'.format(**locals())

基于： https ://pyformat.info/

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