Questions tagged [untagged]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
3
votes
1answer
940 views

What does seeding mean in rand function?

what does seeding mean? in pset3 generate.c they have called srand() if seed number is given or srand((unsigned int) time(NULL)); what does time(null) do? after this for each random number to be ...
9
votes
1answer
2k views

cs50w project1 - AttributeError: 'NoneType' object has no attribute '_instantiate_plugins'

I am trying to import the books.csv file into the online PostgreSQL database via Python code, as shown in the lectures and I get this error message when sqlalchemy is attempting to create the engine. ...
1
vote
2answers
65 views

what is the maximum input value for greedy?

The maximum input value that the "official" reply will calculate is 21474834 which gives an answer of 85899339; which is correct. However if 21474835, or anything higher, is input, the answer is 0. ...
0
votes
1answer
147 views

Error when fetching data from Heroku Postgresql: AttributeError: 'NoneType' object has no attribute '_instantiate_plugins'

I am getting the following error while fetching data from Heroku, Traceback (most recent call last): File "list.py", line 6, in <module> engine = create_engine(os.getenv("DATABASE_URL")) ...
0
votes
1answer
99 views

why cant i use the hexadecimal codes in my program?

whodunit.c:77:40: error: invalid digit 'f' in octal constant if (triple.rgbtRed == 0000ff) whodunit.c:79:33: error: equality comparison result unused [-Werror,-Wunused-comparison]