import string, pythis, pythat
...
...
...
...
def func():
     blah
     blah
     blah
     from pysomething import foo
     foo()
     etc
     etc
     etc
...
...
...

>>> def f():
    from time import time
    print time()

>>> dis.dis(f)
  2           0 LOAD_CONST               1 (-1)
              3 LOAD_CONST               2 (('time',))
              6 IMPORT_NAME              0 (time)
              9 IMPORT_FROM              0 (time)
             12 STORE_FAST               0 (time)
             15 POP_TOP

  3          16 LOAD_FAST                0 (time)
             19 CALL_FUNCTION            0
             22 PRINT_ITEM
             23 PRINT_NEWLINE
             24 LOAD_CONST               0 (None)
             27 RETURN_VALUE

>>> def g():
    print time()

>>> dis.dis(g)
  2           0 LOAD_GLOBAL              0 (time)
              3 CALL_FUNCTION            0
              6 PRINT_ITEM
              7 PRINT_NEWLINE
              8 LOAD_CONST               0 (None)
             11 RETURN_VALUE

def detect(self):
    import foobar

from prerequisite import foo