What I want to implement in Python:
# 1. define int_factory
# 2. get new id of value 123 --> give 0 to 123
a = int_factory[123]
print(a) # = 0
# 3. get new id of value 12324 --> give 1 to 12324
a = int_factory[12324]
print(a) # = 1
# 4. Hey, what's 123's id?
a = int_factory[123]
print(a) # = 0
# 5. get new id of value 513 --> give next id, which is 2 to 513
a = int_factory[513]
print(a) # = 2
I'd like to implement it using a dictionary data type, or defaultdict in Python.
What I tried:
In [2]: def func():
...: for i in range(10**15):
...: yield i
...:
In [3]: a = defaultdict(func)
In [4]: next(a[123])
But this doesn't work.
Is there a more elegant way to implement this in Python?
I would do it following way:
import collections
import itertools
cnt = itertools.count()
int_factory = collections.defaultdict(cnt.__next__)
print(int_factory[123])
print(int_factory[12324])
print(int_factory[123])
print(int_factory[513])
Output:
0
1
0
2
Explanation: You need to deliver callable when creating collections.default_dict, which will return desired value for missing key