I have been trying for a long time now to discover and/or Google myself to an answer on this. In a genetic algorithm I wrote, rand_funcs is to be filled with appropriate randomization functions for genes within a sequence. In this case, it should be filled with two random functions: one generating a random number between 0 and 2 and the other a random number between 0 and 74.
However, as you can see from the following code and the output generated, the result is that both functions generate numbers between 0 and 2. How is this possible? I even tried using deepcopy on max_nr before giving it to the lambda function creator.
Any advice is appreciated!
self.gene_types = ["int74","int2"]
self.sequence_length = len(gene_types)
self.rand_funcs = []
maxnrs = []
for gt in self.gene_types:
print(gt, file=sys.stderr)
if gt == "bit":
self.rand_funcs.append(lambda: random.random() < 0.5)
elif gt == "float":
self.rand_funcs.append(random.random)
elif gt[:3] == "int":
print("laaaaal", id(gt), gt[3:], file=sys.stderr)
max_nr = int(gt[3:]) #WHY IS THIS EQUAL TO TWO FOR BOTH AFTER SECOND ITERATION?!?!??!
maxnrs.append(int(gt[3:]))
print(maxnrs, max_nr, type(max_nr), id(max_nr), file=sys.stderr)
print(*map(id, maxnrs), file=sys.stderr)
if len(self.rand_funcs) >= 1:
print("meep meep", self.rand_funcs[0](), file=sys.stderr)
print(*map(id, maxnrs), file=sys.stderr)
self.rand_funcs.append(lambda: random.randint(0,max_nr))
print(*map(id, self.rand_funcs), file=sys.stderr)
for f in self.rand_funcs:
print("meep", f(), file=sys.stderr)
else:
raise ValueError("Unknown gene type")
print(self.rand_funcs[0](), file=sys.stderr)
print(self.rand_funcs[1](), file=sys.stderr)
print("maxes", maxnrs, file=sys.stderr)
This is the output:
int74
laaaaal 140047932053576 74
[74] 74 <class 'int'> 94881069021088
94881069021088
140047869933360
meep 73
int2
laaaaal 140047932053632 2
[74, 2] 2 <class 'int'> 94881069018784
94881069021088 94881069018784
meep meep 2
94881069021088 94881069018784
140047869933360 140047869933496
meep 0
meep 1
2
1
maxes [74, 2]
