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Steven Hender5,830 Points
In Python I have a problems re-assigning '__imul__' I call 'NumString(3) *= 2' and it returns Syntax Error
I can get the add and multiplication to run just fine with mul and rmul , it is the imul that has stumped me on this question.
The Exercise Question reads: Challenge Task 2 of 2
Now wrap it up by adding in imul, which does in-place multiplication. Be sure to update self.value!
My Answer: / problem code reads:
class NumString: def __mul__(self, other): if '.' in self.value: return float(self) * other return int(self) * other def __rmul__(self, other): self.value = self * other return self.value def __imul__(self, other): self.value = self.value * other return self.value
The returned error is:
>>> from numstring import NumString >>> NumString(3) *= 2 File "<stdin>", line 1 SyntaxError: can't assign to function call >>>
Can anyone help? Thankyou :)
class NumString: def __init__(self, value): self.value = str(value) def __mul__(self, other): if '.' in self.value: return float(self) * other return int(self) * other def __rmul__(self, other): self.value = self * other return self.value def __imul__(self, other): self.value = self * other return self.value def __str__(self): return self.value def __int__(self): return int(self.value) def __float__(self): return float(self.value) def __add__(self, other): if '.' in self.value: return float(self) + other return int(self) + other def __radd__(self, other): return self + other def __iadd__(self, other): self.value = self + other return self.value
Chris FreemanTreehouse Moderator 68,064 Points
The function call
NumString(3) used to create the instance cannot be on the left side of a iterative statement. Break it in two statements give you:
# Using simple multiply works >>> NumString(3) <NumString object at 0x7f5df4f58a20> >>> NumString(3) * 3 9 # but iterative multiply fails because this: >>> NumString(3) *= 3 # is the same as >>> NumString(3) = NumString(3) * 3 # Breaking it in two parts works: >>> ns = NumString(3) >>> ns <imul.NumString object at 0x7f5df4f58a20> >>> print(ns) 3 >>> ns *= 3 >>> ns '333'
The result is
'333' because a string times an integer n returns the string repeated n times. If you wish to preserve the class, you will need to figure out how to multiply as numbers, then reassign
self.value as a string. Lastly, remember to return self
Post back if you need more help. Good luck!!