Question

I need to replace some letters into a List with numbers (each letter is encoded to a number). I used this structure:

r = []
for x in some_list:
    if x in "ABCDE":
        r.append({"A":10, "B":20, "C":30, "D":40, "E":50}[x])
    else:
        r.append(int(x)) # convert string digit to digit
some_list = r

(some_list being mutable as in this code).

I wish to ask if there are some more compact structures in python (less code) that can make this encoding and run faster.

Answer 1

How about

d = {"A":10, "B":20, "C":30, "D":40, "E":50}
some_list = [int(d.get(x, x)) for x in some_list]

Other ways to write that list comprehension include:

some_list = [d.get(x) or int(x) for x in some_list]
some_list = [d[x] if x in d else int(x) for x in some_list]