Program to replace each string with an integer value in a given list of strings

You can use list compréhension :

[sum([ord(i) for i in word]) for word in list_rivers]

it's equivalent to do

tmp_1 = []
for word in list_rivers:
    tmp_2 = []
    for i in word:
        tmp_2.append(ord(i))
    tmp_1.append(sum(tmp_2))

As iElden mentions, you may use list comprehension here. Note that in this case, doing so does not necessarily optimize your code for efficiency.

Your method:

%%timeit
river = []
for i in list_rivers:
    num=0
    for j in i:
        num = num + ord(j)
    river.append(num)

 # 100000 loops, best of 3: 6.57 µs per loop

List comprehension:

%%timeit
result = [sum([ord(i) for i in word]) for word in list_rivers]

# 100000 loops, best of 3: 9.37 µs per loop

(Even slower) using map:

%%timeit
result = map(lambda x: sum([ord(letter) for letter in x]), list_rivers)

# 100000 loops, best of 3: 10.3 µs per loop

It says write a program to do it, so here's a program to do so. Example output: [597, 813, 1143, 692, 619, 787, 610, 514]

def string_to_int(string):
    retval = 0
    for c in string:
        retval += ord(c)
    return retval


def main(data):
    retval = []
    for item in data:
        retval.append(string_to_int(item))
    return retval


if __name__ == "__main__":
    list_rivers = ["Ganges", "Godavari", "Brahmaputra", "Narmada", "Yamuna", "Mahanadi", "Kaveri", "Tapti"]
    results = main(list_rivers)
    print results