pip install pycocotools

出现如下bug，则：

File "/...../lib/python3.6/site-packages/pycocotools/coco.py", line 308, in loadRes
if type(resFile) == str or type(resFile) == unicode:

NameError: name 'unicode' is not defined

解决：pip install -U 'git+ https://github.com/cocodataset/cocoapi.git#subdirectory=PythonAPI '