Is there a better way to use multiple OR in dict comprehension?-CodePudding

x = {'a': (2, 3), 'b': (4, 1), 'c': (3, 2), 'd': (1, 0), 'e': (2, 0)} 
x = {
    k: v
    for k, v in x.items()
    if (v[0] >= 2 and v[1] >= 0) or (v[0] >= 1 and v[1] > 1)
}
print(x)

In the 'if' block, I have a lot of logical 'or' enclosed with parenthesis. Is there better way to express it in dict comprehension?

Also, I can omit the () in the 'if' statement to make it more consise. Right?

CodePudding user response：

You can unpack the tuple. Keep the parentheses; and technically has a higher precedence than or, but not everyone knows that and this makes it more readable:

x = {k: (fst, snd) for k, (fst, snd) in x.items() if (fst >= 2 and snd >= 0) or (fst >= 1 and snd > 1)}

This outputs:

{'a': (2, 3), 'b': (4, 1), 'c': (3, 2), 'e': (2, 0)}

CodePudding user response：

In the 'if' block, I have a lot of logical 'or' enclosed with parenthesis. Is there better way to express it in dict comprehension?

No. Your both "main" conditions have one constraint that is a superset of the same constraint of the other side, and one that is incompatible.

Three boolean operators is the minimum you can do.

CodePudding user response：

One option is to write a function that checks for whether or not you want to include the item:

def my_filter(tup):
    return (tup[0] >= 2 and tup[1] >= 0) or (tup[0] >= 1 and tup[1] > 1)

x = {'a': (2, 3), 'b': (4, 1), 'c': (3, 2), 'd': (1, 0), 'e': (2, 0)} 
y = {
    k: v
    for k, v in x.items()
    if my_filter(v)
}
print(y)

Or you could wrap both conditions with any:

z = {
    k: v
    for k, v in x.items()
    if any(
        [v[0] >= 2 and v[1] >= 0,
         v[0] >= 1 and v[1] > 1]
    )
}
print(z)

Both of these will output:

{'a': (2, 3), 'b': (4, 1), 'c': (3, 2), 'e': (2, 0)}

TIO