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Python Python Collections (2016, retired 2019) Sets Set Math

Douglas North
Douglas North
10,884 Points
Posted by Douglas North
Douglas North
10,884 Points

sets.py

It may be that I have exhausted myself today and can't see the obvious. could you direct me towards fixing my code?

sets.py 
COURSES = {
    "Python Basics": {"Python", "functions", "variables",
                      "booleans", "integers", "floats",
                      "arrays", "strings", "exceptions",
                      "conditions", "input", "loops"},
    "Java Basics": {"Java", "strings", "variables",
                    "input", "exceptions", "integers",
                    "booleans", "loops"},
    "PHP Basics": {"PHP", "variables", "conditions",
                   "integers", "floats", "strings",
                   "booleans", "HTML"},
    "Ruby Basics": {"Ruby", "strings", "floats",
                    "integers", "conditions",
                    "functions", "input"}
}
def covers(param1):
    r_list = []
    for k,v in COURSES.items():
        if param1 | v:
            r_list.append(k)
    return r_list

def covers_all(single_set):
    new_list = []
    for key, value in COURSES.items():
        if single_set & value:
            new_list.append(key)
    return new_list

2 Answers

Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 28,720 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 28,720 Points

I am not sure what you are trying to accomplish with your code, but I noticed two issues:

  1. use of bitwise operators "|" and "&" rather than logical operators such as "or", "and", or "in".

  2. malformed COURSES dictionary. All dictionaries are formed by key-value pairs. {"key" : value}. Typically the key is a string, and the value can be any kind of object or nested object. To me it looks like you want a list... so you should replace the curly braces with square brackets. see below

COURSES = {
    "Python Basics": ["Python", "functions", "variables",
                      "booleans", "integers", "floats",
                      "arrays", "strings", "exceptions",
                      "conditions", "input", "loops"],
    "Java Basics": ["Java", "strings", "variables",
                    "input", "exceptions", "integers",
                    "booleans", "loops"],
    "PHP Basics": ["PHP", "variables", "conditions",
                   "integers", "floats", "strings",
                   "booleans", "HTML"],
    "Ruby Basics": ["Ruby", "strings", "floats",
                    "integers", "conditions",
                    "functions", "input"]
}

This is what you might have been trying to do... so look over the output and see if this is what you intended.

def covers(param1):
    r_list = []
    for k,v in COURSES.items():
        if param1 in v:
            r_list.append(k)
    return r_list

def covers_all(single_set):
    new_list = []
    for key, value in COURSES.items():
        if single_set in key:
            new_list.append((key,value))
    return new_list


# maybe you want to do something like this?
print "Courses which cover 'strings'"
print covers("strings") # find which courses cover "strings"

print "What topics are in courses with 'Java' in the title"
print covers_all("Java") # find what topics are in any courses with "Java" in the title

output is:

Courses which cover 'strings'
['Python Basics', 'Ruby Basics', 'Java Basics', 'PHP Basics']
What topics are in courses with 'Java' in the title
[('Java Basics', ['Java', 'strings', 'variables', 'input', 'exceptions', 'integers', 'booleans', 'loops'])]
Douglas North
Douglas North
10,884 Points
Douglas North
Douglas North
10,884 Points

Hey Jeff, thanks for the response :) The dictionary was provided and they wanted me to use these set functions. It took a 2 hour break and a tea but i found that there were more functions i didn't know about it works with =< instead of &.also

thank you