Expecting value: line 1 column 1 (char 0) with banal json.load()?

Question

Python

here in this piece of code I load json file

def set_mat(id):  
            global users_mat
            if not str(id) in os.listdir('mat/'):
                os.mkdir(str('mat/'+str(id)))
                with open("mat/" + str(id) + "/users_mat.json", 'w+') as f:
                    json.dump({'mats':{},'send_time' : {'hour': 9, 'min': 0, 'is_on': 1}, 'last_time':{'day':time.strptime(time.asctime()).tm_yday-1}}, f)
            with open("mat/" + str(id) + "/users_mat.json", 'r') as f:
                users_mat = json.load(f)
                print (str(json.load(f)))
            return users_mat
        def mat_filter(message):  #
            def mat_write(message, word):
                set_mat(message.chat.id)
                for mat in cfg.mat_list:
                    if mat.lower() in word.lower():
                        if not str(message.from_user.id) in users_mat['mats'].keys():
                            with open("mat/" + str(message.chat.id) + "/users_mat.json", 'w+') as f:
                                users_mat['mats'][str(message.from_user.id)] = 0
                                json.dump(users_mat, f)
                with open("mat/" + str(message.chat.id) + "/users_mat.json", 'w+') as f:
                    users_mat['mats'][str(message.from_user.id)] = users_mat['mats'][str(message.from_user.id)] + 1
                    json.dump(users_mat, f)
            wordm = ''
            x = 0
            for i in message.text:
                x += 1
                if x == len(message.text):
                    mat_write(message, wordm)
                    wordm = ''
                    break
                if i == '\n':
                    continue
                if i != ' ':
                    wordm += i

                else:
                    mat_write(message, wordm)
                    wordm = ''

I call the mat_filter function, which in turn calls set_mat , inside which I create a jane file of the format {'hour': 9, 'min': 0, 'is_on': 1}, 'last_time':{'day':time .strptime(time.asctime()).tm_yday-1}} , and then I read it but when reading (json.load()) an error occurs:
020-11-17 16:48:36,384 (util.py:75 WorkerThread1 ) ERROR - TeleBot: "JSONDecodeError occurred, args=('Expecting value: line 1 column 1 (char 0)',)
Traceback (most recent call last):
File "C:\Users\abraham\AppData\Local\Programs\ Python\Python38-32\lib\site-packages\telebot\util.py", line 69, in run
task(*args, **kwargs)
File "C:/Users/abraham/Desktop/...", line 186, in reaction
mat_filter(message)
File "C:/Users/abraham/Desktop/...", line 46, in mat_filter
mat_write(message, wordm)
File "C:/Users/abraham/Desktop/...", line 31, in mat_write
set_mat( message.chat.id)
File "C:/Users/abraham/Desktop/...", line 27, in set_mat
print (str(json.load(f)))
File "C:\Users\abraham\AppData\ Local\Programs\Python\Python38-32\lib\json\__init__.py", line 293, in load
return loads(fp.read(),
File "C:\Users\abraham\AppData\Local\Programs\Python\ Python38-32\lib\json\__init__.py", line 357, in loads
return _default_decoder.decode(s)
File "C:\Users\abraham\AppData\Local\Programs\Python\Python38-32\lib\json\ decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "C:\Users\abraham\AppData\Local\Programs\Python\Python38-32\lib\json\decoder. py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

and yes, I'm sure that the condition to create file passes, since I specifically delete it! after error - file remains empty...

Answer 1

users_mat = json.load(f)
print (str(json.load(f)))

Read the file to the end, parse it, and then try to print the result of parsing the end of the file.