variable inside function not defined despite having it defined globally
Question:
I define my dictionary ‘frame_dict’ outside my for loop. However, when it gets to my forFrame function, despite setting it has a global variable, I get an error saying that frame_dict is not defined. Any help?
import os
from imageai.Detection import VideoObjectDetection
import pickle
PATH_TO_STORE_VIDEOS = "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/Videos"
tv_commercial_videos = os.listdir('Videos/')
def yolo_neural_network(path_to_videos, tv_commercials):
execution_path = os.getcwd()
frame_dict = {}
for tv_c in tv_commercials:
frame_dict.setdefault(tv_c,[])
# Use pre trained neural network to label things in videos
vid_obj_detect = VideoObjectDetection()
# Set and load Yolo model
vid_obj_detect.setModelTypeAsYOLOv3()
vid_obj_detect.setModelPath(os.path.join(execution_path,"yolov3.pt"))
vid_obj_detect.loadModel()
input_file_path = os.path.join(path_to_videos, tv_c)
if not os.path.exists("output_from_model_yolov3/"):
os.makedirs("output_from_model_yolov3/")
output_file_path = os.path.join(execution_path,"output_from_model_yolov3/", "model_yolov3_output_" + tv_c)
def forFrame(frame_number, output_array, output_count):
global frame_dict
frame_dict[tv_c].append(output_count)
return frame_dict
vid_obj_detect.detectObjectsFromVideo(
input_file_path=input_file_path,
output_file_path=output_file_path,
log_progress=True,
frame_detection_interval= 60,
minimum_percentage_probability=70,
per_frame_function=forFrame,
save_detected_video=True
)
# save dictionary
f = open("yolo_dict.pkl", "wb")
# write dict to pickle file
pickle.dump(frame_dict, f)
# close file
f.close()
return frame_dict
yolo = yolo_neural_network(PATH_TO_STORE_VIDEOS, tv_commercial_videos)
Exception has occurred: ValueError
An error occured. It may be that your input video is invalid. Ensure you specified a proper string value for 'output_file_path' is 'save_detected_video' is not False. Also ensure your per_frame, per_second, per_minute or video_complete_analysis function is properly configured to receive the right parameters.
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 35, in forFrame
frame_dict[tv_c].append(output_count)
NameError: name 'frame_dict' is not defined
During handling of the above exception, another exception occurred:
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 38, in yolo_neural_network
vid_obj_detect.detectObjectsFromVideo(
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 59, in <module>
I tried setting my frame_dict variable as global inside the forframe function expecting it to recognise it.
Answers:
The problem you are facing is that frame_dict is actually not a global variable. It is defined inside of yolo_neural_network. While this is indeed outside forFrame, it is not a global variable.
In this scenario, you should simply remove the global statement, because it is not a global variable you are importing.
frame_dict is not a global, it is just in an outer scope, remove global keyword
Since you mutate the object, you don’t need to do anything more:
def forFrame(frame_number, output_array, output_count):
frame_dict[tv_c].append(output_count)
return frame_dict
Since you don’t assign anything to frame_dict, even if the variable were a global variable, you wouldn’t need to add the global keyword if you mutate the object. global is useful only if you need to assign a new value to the variable.
I define my dictionary ‘frame_dict’ outside my for loop. However, when it gets to my forFrame function, despite setting it has a global variable, I get an error saying that frame_dict is not defined. Any help?
import os
from imageai.Detection import VideoObjectDetection
import pickle
PATH_TO_STORE_VIDEOS = "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/Videos"
tv_commercial_videos = os.listdir('Videos/')
def yolo_neural_network(path_to_videos, tv_commercials):
execution_path = os.getcwd()
frame_dict = {}
for tv_c in tv_commercials:
frame_dict.setdefault(tv_c,[])
# Use pre trained neural network to label things in videos
vid_obj_detect = VideoObjectDetection()
# Set and load Yolo model
vid_obj_detect.setModelTypeAsYOLOv3()
vid_obj_detect.setModelPath(os.path.join(execution_path,"yolov3.pt"))
vid_obj_detect.loadModel()
input_file_path = os.path.join(path_to_videos, tv_c)
if not os.path.exists("output_from_model_yolov3/"):
os.makedirs("output_from_model_yolov3/")
output_file_path = os.path.join(execution_path,"output_from_model_yolov3/", "model_yolov3_output_" + tv_c)
def forFrame(frame_number, output_array, output_count):
global frame_dict
frame_dict[tv_c].append(output_count)
return frame_dict
vid_obj_detect.detectObjectsFromVideo(
input_file_path=input_file_path,
output_file_path=output_file_path,
log_progress=True,
frame_detection_interval= 60,
minimum_percentage_probability=70,
per_frame_function=forFrame,
save_detected_video=True
)
# save dictionary
f = open("yolo_dict.pkl", "wb")
# write dict to pickle file
pickle.dump(frame_dict, f)
# close file
f.close()
return frame_dict
yolo = yolo_neural_network(PATH_TO_STORE_VIDEOS, tv_commercial_videos)
Exception has occurred: ValueError
An error occured. It may be that your input video is invalid. Ensure you specified a proper string value for 'output_file_path' is 'save_detected_video' is not False. Also ensure your per_frame, per_second, per_minute or video_complete_analysis function is properly configured to receive the right parameters.
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 35, in forFrame
frame_dict[tv_c].append(output_count)
NameError: name 'frame_dict' is not defined
During handling of the above exception, another exception occurred:
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 38, in yolo_neural_network
vid_obj_detect.detectObjectsFromVideo(
File "/Users/jaime.pereira/Library/CloudStorage/OneDrive-OneWorkplace/Benchmark_Project/debug.py", line 59, in <module>
I tried setting my frame_dict variable as global inside the forframe function expecting it to recognise it.
The problem you are facing is that frame_dict is actually not a global variable. It is defined inside of yolo_neural_network. While this is indeed outside forFrame, it is not a global variable.
In this scenario, you should simply remove the global statement, because it is not a global variable you are importing.
frame_dict is not a global, it is just in an outer scope, remove global keyword
Since you mutate the object, you don’t need to do anything more:
def forFrame(frame_number, output_array, output_count):
frame_dict[tv_c].append(output_count)
return frame_dict
Since you don’t assign anything to frame_dict, even if the variable were a global variable, you wouldn’t need to add the global keyword if you mutate the object. global is useful only if you need to assign a new value to the variable.