Temporal Dead Zone in Python

```
y = 1
def f(x):
    print(y)
    if True:
        print("true")
        y = 3
    else:
        print("false")
    print(y)
    
f(4)
```
This program should give
```
UnboundLocalError: local variable 'y' referenced before assignment
```
but currently gives no error:
```
undefined
"true"
3
undefined
```
Program: https://share.sourceacademy.org/25fj7
