perl 和 python中的回调函数

就是向函数的参数为   一个函数的引用
sub  callback1 {
    ......
}

sub  callback2 {
   ......
}

sub run {
   my $func_ref = shift;
  .....
  ....
}
if (a>b) {
     run(&callback1);
}
else {
    run(&callback2);
}


def my_callback(input):
    print "function my_callback was called with %s input" % (input,)


def caller(input, func):
    func(input)


for i in range(5):
    caller(i, my_callback)


C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/cookbook/a3.py
function my_callback was called with 0 input
function my_callback was called with 1 input
function my_callback was called with 2 input
function my_callback was called with 3 input
function my_callback was called with 4 input


def apply_async(func, args,  callback):
# Compute the result
  result = func(*args)
# Invoke the callback with the result
  callback(result)
def print_result(result):
    print('Got:', result)
def add(x, y):
    return x + y*2
print  apply_async(add, (2, 3), print_result)

C:Python27python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/cookbook/a4.py
('Got:', 8)
None