Is a list increasing?

incr.py

# Determine whether a list L is increasing. Return True or False.
def incr(L):
    if len(L) < 2:
        # An empty list or a single-value list is counted as increasing.
        return True
    answer = True
    i      = 1
    while True:
        if i >= len(L):
            # We got to the end without returning False, so the answer must be True.
            return True
        if L[i] > L[i-1]:
            # This part of the list is increasing; do nothing.
            pass
        else:
            # We found a part that is not increasing; return False.
            return False
        # Increase the index so we consider the next part of the list.
        i = i + 1

# Test the incr(L) function with a few different values.
# If a test fails, an error will occur.
# If nothing happens, all tests passed.
def test_incr():
    assert incr([]) == True
    assert incr([4]) == True
    assert incr([3,4,7,9,11,20]) == True
    assert incr([3,4,7,2,11,20]) == False
    assert incr([3,4,7,7,11,20]) == False

# To run the test, type test_incr() in the right-hand side of repl.it.