Here is my code.
https://paste.pythondiscord.com/HAPA
#🔒 Need Help with converting the function to use dicts instead of if-else blocks
full linden
crimson yarrowBOT
Here is my code.
https://paste.pythondiscord.com/HAPA
@full linden
Python help channel opened
full linden
@gray skiff
Thank you in advance for the help.
So, I have this code, fully functional, but it's just sooo long with all the if-else blocks, and would like to make it as short and simple as possible, more pythonic in a sense.
Right now, all the dict approaches I tried become massive, and just make the code harder to read than making it shorter.
gray skiff
the first low-hanging fruit i noticed is this series of if statements here
in which, you could use a dict
full linden
Case in point
gray skiff
give me a sec to type it out
full linden
Of course, please take your time.
gray skiff
wait hold on
full linden
Yes?
gray skiff
what are circ.X, circ.Y, etc.?
like their types
i need to know if they are hashable
full linden
Oh, they're methods.
Actually, they could be treated as objects as well.
Like I can use them as an object.
full linden
class _PauliX(Pauli, common_gates.XPowGate):
def __init__(self):
Pauli.__init__(self, index=0, name='X')
common_gates.XPowGate.__init__(self, exponent=1.0)
def __pow__(self, exponent: 'cirq.TParamVal') -> common_gates.XPowGate:
return common_gates.XPowGate(exponent=exponent) if exponent != 1 else _PauliX()
def _with_exponent(self, exponent: 'cirq.TParamVal') -> common_gates.XPowGate:
return self.__pow__(exponent)
@classmethod
def _from_json_dict_(cls, exponent, global_shift, **kwargs):
assert global_shift == 0
assert exponent == 1
return Pauli._XYZ[0]
@property
def basis(self) -> Dict[int, '_XEigenState']:
from cirq.value.product_state import _XEigenState
return {+1: _XEigenState(+1), -1: _XEigenState(-1)}
X = _PauliX()
you could do something like this pattern
if_true is a mapping from your parameters['sub_gate'] field to functions
you could also apply that to a few of the other if/else's below it
full linden
I am sort of aiming for sth like what I did here:
def convert(self,
circuit_framework: Type[Circuit]) -> Circuit:
converted_circuit = circuit_framework(self.num_qubits, self.num_clbits)
gate_mapping: dict[str, Callable] = {
'RX': converted_circuit.RX,
'RY': converted_circuit.RY,
'RZ': converted_circuit.RZ,
'H': converted_circuit.H,
'X': converted_circuit.X,
'Y': converted_circuit.Y,
'Z': converted_circuit.Z,
'S': converted_circuit.S,
'T': converted_circuit.T,
'U3': converted_circuit.U3,
'SWAP': converted_circuit.SWAP,
'CX': converted_circuit.CX,
'CY': converted_circuit.CY,
'CZ': converted_circuit.CZ,
'CH': converted_circuit.CH,
'CS': converted_circuit.CS,
'CT': converted_circuit.CT,
'CRX': converted_circuit.CRX,
'CRY': converted_circuit.CRY,
'CRZ': converted_circuit.CRZ,
'CU3': converted_circuit.CU3,
'CSWAP': converted_circuit.CSWAP,
'MCX': converted_circuit.MCX,
'MCY': converted_circuit.MCY,
'MCZ': converted_circuit.MCZ,
'MCH': converted_circuit.MCH,
'MCS': converted_circuit.MCS,
'MCT': converted_circuit.MCT,
'MCRX': converted_circuit.MCRX,
'MCRY': converted_circuit.MCRY,
'MCRZ': converted_circuit.MCRZ,
'MCU3': converted_circuit.MCU3,
'MCSWAP': converted_circuit.MCSWAP,
'GlobalPhase': converted_circuit.GlobalPhase,
'measure': converted_circuit.measure
}
for gate_info in self.circuit_log:
gate_name = gate_info['gate']
gate_info = dict(list(gate_info.items())[1:])
gate_mapping[gate_name](**gate_info)
return converted_circuit
All of this is to basically avoid having if-else blocks.
gray skiff
Yes, Python doesnt have Rust's much cleaner match which would be a perfect application for this
Which is unfortunate
full linden
But I am also learning what is considered "pythonic", so please let me know if the one you shown is considered good practice and I can adapt that.
full linden
Yes, Python doesnt have Rust's much cleaner `match` which would be a perfect app...
Hehe, I'll consider making the package I have later in Rust as well.
gray skiff
"Pythonic" is subjective but it generally just means doing things in a way that takes advantage of the language's unique characteristic
characteristics*
full linden
Yeah.
gray skiff
for example, functions are first class objects
So since you have a long chain of if/else's where you just call different functions, have a mapping from conditions to functions instead
Which you've already done
My code example earlier simply replicates the additional logic you have of also checking for the len(parameters['control_qid_shape'])
full linden
Yeah, but in this one that we're talking about now issue is the inconsistency of the parameters passed and the nested ifs.
gray skiff
But it follows the same general pattern that you've shown in that latest codeblock
full linden
My code example earlier simply replicates the additional logic you have of also ...
Yeah, I guess some if-else blocks become inevitable.
full linden
you could do something like this pattern
Is yours inside the loop?
or outside?
I am sort of considering using lambda to define the dict outside once, instead of defining it everytime inside the loop.
gray skiff
It's in the same context as everything under your "elif gate_type == 'ControlledGate'"
So it's inside the loop
gray skiff
I don't see why you can't already have the mapping dict outside the loop?
circuit already exists before the loop, right?
full linden
I don't see why you can't already have the mapping dict outside the loop?
Yes, but wouldn't it be re-defining the dict everytime?
Like
x = 1
vs
for _ in range(10):
x = 1
Yes, if it were inside the loop
But I'm saying, you can have it outside the loop already
With how your code is
given that circuit exists outside the loop
So everything you need to map to, i.e. circuit's methods, already exist
For this codeblock, I don't think you need a mapping dict
It's small, and you have one outlier case being ZPowGate which would be awkward having to have an if-statement separate from the mapping since there's no way to cleanly fit the logic for ZPowGate inside the mapping without defining an external function (unnecessary complexity) or having an obnoxiously long lambda
Anyway, seems you have Opal helping you already
I'm going to have dinner
full linden
Anyway, seems you have Opal helping you already
Yeah, he also agrees with this dict thing being weird for this case.
crimson yarrowBOT
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