input_list = ["G1","G2","G5","G4","G3","R1","R2","R3","R5","R4"]
output_list = ["R1","R2","R3","R4","R5""G1","G2","G3","G5","G4"]
Code I tried:
new_list = []
for i in sorted(input_list):
new_list.append(i)
print (new_list[::-1])
Actual Output : ['R5', 'R4', 'R3', 'R2', 'R1', 'G5', 'G4', 'G3', 'G2', 'G1']
Expected Output : ["R1", "R2", "R3", "R4", "R5", "G1", "G2", "G3", "G5", "G4"]
It appears that you want to sort descending by the letter component followed by ascending by the number component. One option uses list sort() with a lambda expression:
input_list = ["G1","G2","G5","G4","G3","R1","R2","R3","R5","R4"]
input_list.sort(key=lambda x: (re.sub(r'\d+$', '', x), -int(re.sub(r'^[A-Z]+', '', x))), reverse=True)
print(input_list)
This prints:
['R1', 'R2', 'R3', 'R4', 'R5', 'G1', 'G2', 'G3', 'G4', 'G5']
I'm as much of a fan of regular expressions as the next guy, but assuming the elements of the input list are uniform (a single capital letter followed by a single digit), I believe something (arguably) simpler is possible.
unsorted_list = ["G1","G2","G5","G4","G3","R1","R2","R3","R5","R4"]
sorted_list = sorted(unsorted_list, key=lambda x: (-ord(x[0]), x[1]))
print(sorted_list)
Output:
['R1', 'R2', 'R3', 'R4', 'R5', 'G1', 'G2', 'G3', 'G4', 'G5']
unsorted_list = ["G1","G2","G5","G4","G3","R1","R2","R3","R5","R4"]
sorted_list = sorted(unsorted_list, key=lambda x: (-ord(x[0]), x[1]))
print(sorted_list)
inp = ["R1","G2","R5","G1","R4","R2","R3","G4","G3","G5"] #exp_opt = [R1,R2,R3,R4,R5,G1,G2,G3,G4,G5]
print(sorted(inp))
this is the simplest way to sort things apart from using regex
