When writing python modules, is there a way to prevent it being imported twice by the client codes? Just like the c/c++ header files do:
Python modules aren't imported multiple times. Just running import two times will not reload the module. If you want it to be reloaded, you have to use the
reload statement. Here's a demo
foo.py is a module with the single line
print "I am being imported"
And here is a screen transcript of multiple import attempts.
>>> import foo Hello, I am being imported >>> import foo # Will not print the statement >>> reload(foo) # Will print it again Hello, I am being imported