itertooldict 0.3.3

A missing feature of itertools: labeled product of multiple choices from a dictionary.

itertooldict

A missing feature of itertools: labeled product of multiple choices from a dictionary.

PIP: itertooldict on PyPI

Installation

pip install itertooldict

Usage

productDict takes a dictionary where values are iterables and yields dictionaries representing their Cartesian product.

[!IMPORTANT] collections.OrderedDict is the preferred input type. While standard dictionaries work in modern Python, using OrderedDict ensures that the iteration order and dictionary keys remain consistent across all environments.

from itertooldict import productDict
from collections import OrderedDict

# Preferred usage with OrderedDict
data = OrderedDict([
    ("voltage", ["Vmax", "Vmin"]),
    ("temp", ["hot", "cold"]),
    ("speed", ["highSpeed", "lowSpeed"]),
    ("fw", ["fw1", "fw2", "fw3"])
])

for combo in productDict(data):
    # highSpeed only works on fw3
    if combo['speed'] == 'highSpeed' and combo['fw'] in ['fw1', 'fw2']:
        continue
    print(combo)

# Output:
# {'voltage': 'Vmax', 'temp': 'hot', 'speed': 'highSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmax', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw1'}
# {'voltage': 'Vmax', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw2'}
# {'voltage': 'Vmax', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmax', 'temp': 'cold', 'speed': 'highSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmax', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw1'}
# {'voltage': 'Vmax', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw2'}
# {'voltage': 'Vmax', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmin', 'temp': 'hot', 'speed': 'highSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmin', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw1'}
# {'voltage': 'Vmin', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw2'}
# {'voltage': 'Vmin', 'temp': 'hot', 'speed': 'lowSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmin', 'temp': 'cold', 'speed': 'highSpeed', 'fw': 'fw3'}
# {'voltage': 'Vmin', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw1'}
# {'voltage': 'Vmin', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw2'}
# {'voltage': 'Vmin', 'temp': 'cold', 'speed': 'lowSpeed', 'fw': 'fw3'}

Specifying Key Order

You can use the keyorder argument to specify the order of keys in the resulting dictionaries and the order in which the product is calculated.

data = {"a": [1, 2], "b": ["x", "y"]}
# Iterate with 'b' as the outer loop and 'a' as the inner loop
for combo in productDict(data, keyorder=["b", "a"]):
    print(f"b={combo['b']}, a={combo['a']}")
# b=x, a=1
# b=x, a=2
# b=y, a=1
# b=y, a=2

Compatibility with list() and enumerate()

productDict works seamlessly with standard Python functions:

# Convert to list
all_combos = list(productDict(data))

# Use with enumerate
for i, combo in enumerate(productDict(data)):
    print(f"{i}: {combo}")