But I tested my json with few tools like json_pp, or 'python -c "import sys,json;json.loads(sys.stdin.read());print('OK')"' and there was no problem. I am producing the json the same way all the time ...

Which program is pickling and why? That seems like a very strange thing to do in this situation. The only time to pickle something is if you need to represent a non-string object on disk, but Python ...

I call this API with a JSON file, but i find that the input_data is not received correctly by the python script, how to handle it? The test script is put below ...