Pfthb

This is a function I defined in order to find the smallest value in a list using recursion.However,I called the function twice within itself, which I think it's a bit weird.
Is there a way around the function append()?. We haven't studied it yet so I'm asking whether there could be a simpler way to get the same solution by not using append()?

def minimum(lst):
 """
 parameters : lst of type list
 return : the value of the smallest element in the lst
 """
 if len(lst) == 1:
 return lst[0]

 if lst[0] < lst[1]:
 lst.append(lst[0])
 return(minimum(lst[1:]))
 return(minimum(lst[1:])) 

I guess you could do this to avoid append:

def minimum(lst):

 if len(lst)==1:
 return lst[0]

 if lst[0] < lst[1]:
 return minimum(lst[0:1]+ lst[2:])
 else:
 return minimum(lst[1:])

but i think this one is better with only one call to minimum:

def minimum(lst): 
 if len(lst) == 1:
 return lst[0] 
 s = minimum(lst[1:])

 return s if s < lst[0] else lst[0]

Use an additional variable?

def minimum(lst, current_min=None):
 if not lst:
 return current_min
 if current_min is None:
 current_min = lst[0]
 elif lst[0] < current_min:
 current_min = lst[0]
 return minimum(lst[1:], current_min)

Here's a very explicit version that should be easy to read due to comments and variable names.

def minimum(lst):
 # base case
 if len(lst) == 1:
 return lst[0]

 # get first element and minimum of remaining list
 first = lst[0]
 rest = lst[1:]
 min_of_rest = minimum(rest)

 # return the smaller one of those two values
 if first < min_of_rest:
 return first
 else:
 return min_of_rest

You can use the following program:

def minimum(lst):
"""
parameters : lst of type list
return : the value of the smallest element in the lst
"""
if len(lst) == 1:
 return lst[0]
temp_min = minimum(lst[1:])
if lst[0] < temp_min:
 return lst[0]
else:
 return temp_min

If your task is simply to find the smallest value in a list with any given length, I don't exactly know why you are using recursion. There are more efficient ways to do this such as built-in functions of Python. For example:

def smallest(list):
 return min(list)
list_of_ints = [4,2,7,6,8,1,5,9,2]
print(smallest(list_of_ints))

This will print out 1.