Write a program that determines if a string (passed as a command-line argument) has all unique characters. The program must print the number of times each existing character appears, and then print whether or not they are all unique.

C:\>python unique.py

Usage: python unique.py "Any string you want..."

C:\>python unique.py This is a string!

Usage: python unique.py "Any string you want..."

C:\>python unique.py "This is a string!"

T : 1

h : 1

i : 3

s : 3

: 3

i : 3

s : 3

: 3

a : 1

: 3

s : 3

t : 1

r : 1

i : 3

n : 1

g : 1

! : 1

Not unique! One or more characters appear more than once.

C:\>python unique.py "My string!"

M : 1

y : 1

: 1

s : 1

t : 1

r : 1

i : 1

n : 1

g : 1

! : 1

Unique! All characters appear only once.