L11Q28_Index.py

# Define a procedure, find_element,
# using index that takes as its
# inputs a list and a value of any
# type, and returns the index of
# the first element in the input
# list that matches the value.

# If there is no matching element,
# return -1.
def find_element(input,key):
    '''if key in input:
        return input.index(key)
    return -1
'''
    if key not in input:
        return -1
    return input.index(key)


print find_element([1,2,3],3)
#>>> 2

print find_element(['alpha','beta'],'gamma')
#>>> -1