On 6/29/20 2:16 AM, Peter Otten wrote:
Jim wrote:linux mint 19.3, python 3.6 I wrote a program to download stock info from yahoo using yfinance. I have been running it unchanged for the past 3 months, today it gave an error. When looping through a list of stocks the error is random, never the same position in the list. I wrote the following little test script to show the error: import yfinance as yf import pandas as pd day = '2020-06-25' aapl = yf.Ticker('AAPL') hist = aapl.history(start=day) print(hist) close = hist.loc[day]['Close'] I ran it 10 times 8 times I got a dataframe and 2 times I got the error shown below: (env36) jfb@jims-mint18 ~ $ /home/jfb/EVs/env36/bin/python3 /home/jfb/Dev/Python/test_yfinance.py Open High Low Close Volume Date 2020-06-25 360.70 365.00 357.57 364.84 34380600 2020-06-26 364.41 365.32 353.02 353.63 51270100 (env36) jfb@jims-mint18 ~ $ /home/jfb/EVs/env36/bin/python3 /home/jfb/Dev/Python/test_yfinance.py Traceback (most recent call last): File "/home/jfb/Dev/Python/test_yfinance.py", line 13, in <module> hist = aapl.history(start=day) File "/home/jfb/EVs/env36/lib/python3.6/site-packages/yfinance/base.py", line 155, in history data = data.json() File "/home/jfb/EVs/env36/lib/python3.6/site-packages/requests/models.py", line 897, in json return complexjson.loads(self.text, **kwargs) File "/home/jfb/EVs/env36/lib/python3.6/site-packages/simplejson/__init__.py", line 518, in loads return _default_decoder.decode(s) File "/home/jfb/EVs/env36/lib/python3.6/site-packages/simplejson/decoder.py", line 370, in decode obj, end = self.raw_decode(s) File "/home/jfb/EVs/env36/lib/python3.6/site-packages/simplejson/decoder.py", line 400, in raw_decode return self.scan_once(s, idx=_w(s, idx).end()) simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0) I don't know pandas that well. My only contact with it is when a module I am using depends on it. So does the dataframe look correct? The error complains of line 1, column 1. Just looking at the dataframe it looks like Date is on a different line from the rest of the headers or is that just the result of being printed in the terminal? On the yfinance github issues page there were a few people reporting this error. A couple of people reported a work around using try/except. It worked for some people and not others. It didn't work for me. I'd appreciate any advice you could give.My guess is that pandas is not the source of the problem. The error occurs when simplejson tries to parse an empty string:import simplejson simplejson.loads("")Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib/python3/dist-packages/simplejson/__init__.py", line 488, in loads return _default_decoder.decode(s) File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 370, in decode obj, end = self.raw_decode(s) File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 389, in raw_decode return self.scan_once(s, idx=_w(s, idx).end()) simplejson.scanner.JSONDecodeError: Expecting value: line 1 column 1 (char 0) This probably means that yahoo returns an empty string instead of the expected JSON. If the error occurs only sporadically and you can identify the downloading code in the API source you can try and replace (pseudo-code) json_data = download_from_yahoo() df = dataframe_from_json(json_data) with while True: json_data = download_from_yahoo() if json_data: break time.sleep(1) # wait a moment, then retry download df = dataframe_from_json(json_data)
Thanks, I have it working now by wrapping a for loop in a try/except. When I get a chance I will use yours and MRAB's suggestions to try to figure out just what caused the problem.
Regards, Jim -- https://mail.python.org/mailman/listinfo/python-list
