Question

Explain in detail about cmp() function.

Answer 1

• cmp() was a Python 2 function used to compare two objects, including dictionaries and tuples.
• Its historical form was cmp(x, y).
• It returned:
  • 0 when x and y were equal.
  • A positive value when x was greater than y.
  • A negative value when x was less than y.
• From the source examples: cmp(month, m) returns 0 when both dictionaries are the same; cmp(m, n) returns 1; and cmp(n, m) returns -1.
• cmp() was removed in Python 3. Use comparison operators instead:
  • x == y for equality.
  • x > y to check whether x is greater than y.
  • x < y to check whether x is less than y.
• A Python 3 equivalent returning -1, 0, or 1 is:

result = (x > y) - (x < y)