FileNotFound even files does exit

[Shuvo001]

System information

• Have I written custom code: No
• OS Platform: window10
• Python version: 3.8
• Deep learning framework and version: PyTorch 1.7.1
• Use GPU or not: use GPU
• The network you trained: Faster R-CNN

Describe the current behavior

** I am using a custom Pascal VOC dataset. but my files are named in string form and not integers. So, when I am using str format files I'm getting FileNotFoundError but when I change str to int in JPEGImages and 'filename' in the annotations file I can run my code smoothly. What should i change in my program plzz? **