I have a python3 script located in /home/valence/ that gets the weather forecast for the current day (max and min temperature values in Celsius) from Yahoo! weather API. The file looks exactly like this:

```
#!/usr/bin/python3
from urllib import request
import json
url="https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20weather.forecast%20where%20woeid%3D349859%20and%20u='c'&format=json&diagnostics=true&callback="
response=request.urlopen(url)
str_response = response.readall().decode('utf-8')
dic = json.loads(str_response)
dic["query"]["results"]["channel"]["location"]["region"]="R.M."
low=dic["query"]["results"]["channel"]["item"]["forecast"][0]["low"]
high=dic["query"]["results"]["channel"]["item"]["forecast"][0]["high"]
forecast=open("forecast.txt", "w+")
forecast.write("Minima: "+str(low)+" Maxima: "+str(high))
forecast.close()

```

It works fine when I execute it. It creates or overwrites the file forecast.txt with the right values, but when I try to use cron to execute with the following cron job:

```
* * * * * /home/valence/Get_forecast.py

```

no file forecast.txt is created or modified.

So I need to know what I am doing wrong and how to make this work as intended. The cron job is not meant to be executed every minute (because forecast for a day remains the same throughout the day), but for now I have it that way so I can see changes without having to wait much.

Note: I am new to linux (I am using Lubuntu)