[Tutor] Python Error Message
Alan Gauld
alan.gauld at yahoo.co.uk
Tue Jan 26 20:47:39 EST 2021
I'm forwarding to the list so others can comment....
I've loaded and run your file and (once I mock up unit.py_)
it works with no errors until it tries to load data.
So I'm not seeing the error you are getting which suggests
its an environment issue.
However, looking back at your original post I noticed
something odd that I missed first time:
C:\Users\leitm>python C:\Users\leitm\Desktop\AI\degrees.py
"C:\Users\leitm\Desktop\AI\degrees.py\small"
The argument to degrees.py is a path string.
But the last element of the path is a filename followed
by \small - is that correct?
Your code is looking for a directory!
I don't think that would cause the missing main module
error but you should probably fix it!
The other issue there is that I'm not sure how windows
python will handle that path string with the backslashes.
You may need to escape them or use forward slashes(which
Windows can process with no problems inside a string)
Alan G.
On 27/01/2021 01:42, Alan Gauld via Tutor wrote:
>
> On 26/01/2021 17:18, Nirel Leitman wrote:
>> Here is the main code for degrees.py -- it is very long:
>>
>> import csv
>> import sys
>> from util import Node, StackFrontier, QueueFrontier
>> # Maps names to a set of corresponding person_ids
>> names = {}
>> # Maps person_ids to a dictionary of: name, birth, movies (a set of movie_ids)
>> people = {}
>> # Maps movie_ids to a dictionary of: title, year, stars (a set of person_ids)
>> movies = {}
>> def load_data(directory):
>> """
>> Load data from CSV files into memory.
>> """
>> # Load people
>> with open(f"{directory}/people.csv", encoding="utf-8") as f:
>> reader = csv.DictReader(f)
>> for row in reader:
>> people[row["id"]] = {
>> "name": row["name"],
>> "birth": row["birth"],
>> "movies": set()
>> }
>> if row["name"].lower() not in names:
>> names[row["name"].lower()] = {row["id"]}
>> else:
>> names[row["name"].lower()].add(row["id"])
>> # Load movies
>> with open(f"{directory}/movies.csv", encoding="utf-8") as f:
>> reader = csv.DictReader(f)
>> for row in reader:
>> movies[row["id"]] = {
>> "title": row["title"],
>> "year": row["year"],
>> "stars": set()
>> }
>> # Load stars
>> with open(f"{directory}/stars.csv", encoding="utf-8") as f:
>> reader = csv.DictReader(f)
>> for row in reader:
>> try:
>> people[row["person_id"]]["movies"].add(row["movie_id"])
>> movies[row["movie_id"]]["stars"].add(row["person_id"])
>> except KeyError:
>> pass
>> def main():
>> if len(sys.argv) > 2:
>> sys.exit("Usage: python degrees.py [directory]")
>> directory = sys.argv[1] if len(sys.argv) == 2 else "large"
>> # Load data from files into memory
>> print("Loading data...")
>> load_data(directory)
>> print("Data loaded.")
>> source = person_id_for_name(input("Name: "))
>> if source is None:
>> sys.exit("Person not found.")
>> target = person_id_for_name(input("Name: "))
>> if target is None:
>> sys.exit("Person not found.")
>> path = shortest_path(source, target)
>> if path is None:
>> print("Not connected.")
>> else:
>> degrees = len(path)
>> print(f"{degrees} degrees of separation.")
>> path = [(None, source)] + path
>> for i in range(degrees):
>> person1 = people[path[i][1]]["name"]
>> person2 = people[path[i + 1][1]]["name"]
>> movie = movies[path[i + 1][0]]["title"]
>> print(f"{i + 1}: {person1} and {person2} starred in {movie}")
>> def shortest_path(source, target):
>> """
>> Returns the shortest list of (movie_id, person_id) pairs
>> that connect the source to the target.
>> If no possible path, returns None.
>> """
>> # TODO
>> raise NotImplementedError
>> def person_id_for_name(name):
>> """
>> Returns the IMDB id for a person's name,
>> resolving ambiguities as needed.
>> """
>> person_ids = list(names.get(name.lower(), set()))
>> if len(person_ids) == 0:
>> return None
>> elif len(person_ids) > 1:
>> print(f"Which '{name}'?")
>> for person_id in person_ids:
>> person = people[person_id]
>> name = person["name"]
>> birth = person["birth"]
>> print(f"ID: {person_id}, Name: {name}, Birth: {birth}")
>> try:
>> person_id = input("Intended Person ID: ")
>> if person_id in person_ids:
>> return person_id
>> except ValueError:
>> pass
>> return None
>> else:
>> return person_ids[0]
>> def neighbors_for_person(person_id):
>> """
>> Returns (movie_id, person_id) pairs for people
>> who starred with a given person.
>> """
>> movie_ids = people[person_id]["movies"]
>> neighbors = set()
>> for movie_id in movie_ids:
>> for person_id in movies[movie_id]["stars"]:
>> neighbors.add((movie_id, person_id))
>> return neighbors
>> if __name__ == "__main__":
>> main()
>>
>> Please let me know how I can proceed from here. Thank you again for
>> your assistance.
>>
>> - Nirel
>>
>> On Monday, January 25, 2021, 06:04:41 PM MST, Alan Gauld via Tutor
>> <tutor at python.org> wrote:
>>
>>
>> On 25/01/2021 20:24, Nirel Leitman via Tutor wrote:
>>> I keep getting this error message:
>>> C:\Users\leitm>python C:\Users\leitm\Desktop\AI\degrees.py
>> "C:\Users\leitm\Desktop\AI\degrees.py\small">
>> C:\Users\leitm\AppData\Local\Programs\Python\Python39\python.exe:
>>
>> The error says:
>>> can't find '__main__' module in
>> 'C:\\Users\\leitm\\Desktop\\AI\\degrees.py'
>>
>>> Why can't my computer find my folder?
>>
>> It evidently can, it is a main module that it says is missing not
>> that it can't find the file. It's looking in the file for main
>> and not finding it.
>>
>>> What do I need to change for my computer to read this?
>>
>> It depends on what is in the file.
>> Can you show us the main code for degrees.py?
>>
>>
>> --
>> Alan G
>> Author of the Learn to Program web site
>> http://www.alan-g.me.uk/
>> http://www.amazon.com/author/alan_gauld
>> Follow my photo-blog on Flickr at:
>> http://www.flickr.com/photos/alangauldphotos
>>
>>
>>
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>
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
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