Barcode generation not working with an input value. 

Input not being able to generate an SVG file while the variable item 2 has no issues. 

str(Item1) is redundant but added to create the same code run. 

```
item1=input("Enter a 13 IDN ")
item2=1234567891234

with open("file.svg", "wb") as f:
    EAN13(str(item1), writer=SVGWriter()).write(f)

print(type(item1),type(item2),item1==str(item2))
```