Python虚拟机框架(Python 源码剖析第八章)
frame
1 >>> import sys
2 >>> value = 3
3 >>> def g():
4 frame = sys._getframe()
5 print 'current function is : ', frame.f_code.co_name
6 caller = frame.f_back
7 print 'caller function is : ', caller.f_code.co_name
8 print "caller's local namespace: ", caller.f_locals
9 print "caller's global namespace: ", caller.f_globals.keys()
10
11
12 >>> def f():
13 a = 1
14 b = 2
15 g()
16
17
18 >>> def show():
19 f()
20
21
22 >>> show()
23 current function is : g
24 caller function is : f
25 caller's local namespace: {'a': 1, 'b': 2}
26 caller's global namespace: ['g', 'f', '__builtins__', 'show', 'value', '__package__', 'sys', '__name__', '__doc__']
2 >>> value = 3
3 >>> def g():
4 frame = sys._getframe()
5 print 'current function is : ', frame.f_code.co_name
6 caller = frame.f_back
7 print 'caller function is : ', caller.f_code.co_name
8 print "caller's local namespace: ", caller.f_locals
9 print "caller's global namespace: ", caller.f_globals.keys()
10
11
12 >>> def f():
13 a = 1
14 b = 2
15 g()
16
17
18 >>> def show():
19 f()
20
21
22 >>> show()
23 current function is : g
24 caller function is : f
25 caller's local namespace: {'a': 1, 'b': 2}
26 caller's global namespace: ['g', 'f', '__builtins__', 'show', 'value', '__package__', 'sys', '__name__', '__doc__']
error
1 >>> a = 1
2 >>> def g():
3 print a
4
5
6 >>> def f():
7 print a
8 a = 2
9 print a
10
11
12 >>> g()
13 1
14 >>> f()
15
16 Traceback (most recent call last):
17 File "<pyshell#11>", line 1, in <module>
18 f()
19 File "<pyshell#9>", line 2, in f
20 print a
21 UnboundLocalError: local variable 'a' referenced before assignment
2 >>> def g():
3 print a
4
5
6 >>> def f():
7 print a
8 a = 2
9 print a
10
11
12 >>> g()
13 1
14 >>> f()
15
16 Traceback (most recent call last):
17 File "<pyshell#11>", line 1, in <module>
18 f()
19 File "<pyshell#9>", line 2, in f
20 print a
21 UnboundLocalError: local variable 'a' referenced before assignment
