Return the number of times that the string "hi" appears anywhere in the given string

Sure! Here's the Python code to count the number of times the string "hi" appears in a given string:

def count_hi(string):
    return string.count("hi")

You can call this function with a string argument to get the count of "hi" in that string. For example:

>>> count_hi("hi there hi")
2
>>> count_hi("hiking on a hill")
0
>>> count_hi("hitherehitherehi")
3