I met a problem when practicing high order function. Function "repeated" and "repeated2" are of the same propose.
However, "repeated2" works and returns 8, while "repeated" fails: (this confused me a lot why variable'l' cannot be tracked, but variable 'n' seems work well)
def repeated(f, l):
def h(x):
while l:
x=f(x)
l=l-1
return x
return h
def repeated2(f, n):
def h(x):
k = 0
while k < n:
x, k = f(x), k + 1
return x
return h
result2=repeated2(lambda x:x+1,5)(3)
result=repeated(lambda x:x+1,5)(3)
Traceback (most recent call last):
File "error_code.py", line 18, in <module>
result=repeated(lambda x:x+1,5)(3)
File "error_code.py", line 3, in h
while l:
UnboundLocalError: local variable 'l' referenced before assignment
