Dictionary generated from 2 lists not doing what I want

Question

My problem is this, when given any input (correctly formatted) the dictionary dancer_placings is not correctly generated based on my code. An input of 1 dancer, with number 1, 2 dances, named foo and bar, the dictionary dancer_placings is {'1': {'bar': 0}}, when I want it to be {'1': {'foo': 0},{'bar': 0}}

I have obviously made a mistake, so how can I fix my code so that it does what I intend it to do?

Here is my code:

print("Welcome to Highland Scrutineer")

dancers = []
dances = []
dancer_placings = {}

dancers = []
dancer_num = int(input("How many dancers were there?: "))
while len(dancers) + 1 <= dancer_num:
    dancers.append(input("What was the number of the dancer? "))

print("The list of dancers is:")
for dancer in dancers:
    print(dancer)

dances = []
dance_num = int(input("How many dances did these dancers compete in? "))

while len(dances) + 1 <= dance_num:
    dances.append(input("What was the name of the dance? "))

print("The list of dances is:")
for dance in dances:
    print(dance)

for dancer in dancers:
    for dance in dances:
        dancer_placings.update({dancer:{}})
        dancer_placings[dancer].update({dance:0})

print(dancer_placings)

Answer 1

Your code has a few problems, but I'll just address the ones to make your use case work:

1. You're overwriting the dancerplacings every time:
   dancer_placings.update({dancer:{}})

That's not necessary. That should be up an indentation level.

2. You are currently creating a tuple, which is immutable. You'll need to use a list.

Try this:

print("Welcome to Highland Scrutineer")

dancers = []
dances = []
dancer_placings = {}

dancers = []
dancer_num = int(input("How many dancers were there?: "))
while len(dancers) + 1 <= dancer_num:
    dancers.append(input("What was the number of the dancer? "))

print("The list of dancers is:")
for dancer in dancers:
    print(dancer)

dances = []
dance_num = int(input("How many dances did these dancers compete in? "))

while len(dances) + 1 <= dance_num:
    dances.append(input("What was the name of the dance? "))

print("The list of dances is:")
for dance in dances:
    print(dance)

for dancer in dancers:
    dancer_placings[dancer] = []
    for dance in dances:
        dancer_placings[dancer].append({dance:0})

print(dancer_placings)

---

Thus, this results in the following output:

user-macbookpro2:~ user$ python test.py

Welcome to Highland Scrutineer

How many dancers were there?: 1

What was the number of the dancer? 1

The list of dancers is:

1

How many dances did these dancers compete in? 2

What was the name of the dance? 'foo'

What was the name of the dance? 'bar'

The list of dances is:

foo

bar

{1: [{'foo': 0}, {'bar': 0}]}

---

That appears to be your desired answer!