I don't understand this line:
for symbol, symbol_count in symbols.items():
symbol has never been a variable, is it from the variable symbol_count? If so, how does the code know what symbol is if it has not been a variable or defined?
symbol_count = {
"A": 2,
"B": 4,
"C": 6,
"D": 8
}
def get_slot_machine_spin(rows, cols, symbols):
all_symbols = []
for symbol, symbol_count in symbols.items():
for _ in range(symbol_count):
all_symbols.append(symbol)
The for statement creates variables.
for variable (, othervar, ....) in expression:
In this case, the expression is something which returns pairs of values (so basically, a 2-tuple) and so for can declare two variables and have them receive one value each, similarly to how you can say
symbol, symbol_count = "stack overflow", 42
In some more detail, symbols in this case is apparently a dict variable, and items() loops over the keys and returns one key and its value in each iteration.
Quick demo:
>>> symbols = {"foo": 17, "bar": 42, "baz": 1427}
>>> for symbol, symbol_count in symbols.items():
... print("symbol:", symbol)
... print("count:", symbol_count)
...
symbol: foo
count: 17
symbol: bar
count: 42
symbol: baz
count: 1427
Because the for loop creates a new variable named symbol_count, it is now a local variable which shadows the global dict with the same name; the two are distinct and unrelated, other than in that they share the same name in two separate symbol tables. Perhaps also read up on global vs local scope in Python.
