## Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

### Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial###### Steven Hender

5,830 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
```

## 1 Answer

###### Chris Freeman

Treehouse Moderator 68,423 PointsThe 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!!

## Steven Hender

5,830 Points## Steven Hender

5,830 PointsThankyou :) All good! This makes sense!