为什么无法运行python 函数。如图：左侧是网上的例子。右侧是我的运行结果，显示错误。 为什么我的Python代码运行不了

python \u51fa\u73b0\u8fd9\u4e2a\u9519\u8bef\u662f\u4ec0\u4e48\u539f\u56e0

\u8981\u628a\u4ee3\u7801\u53d1\u73b0\u6765\u624d\u77e5\u9053\uff0c\u4ee5\u4e0b\u662f\u5e38\u89c1\u7684\u9519\u8bef
\u4e0b\u9762\u7ec8\u4e8e\u8981\u8bb2\u5230\u5f53\u4f60\u7528\u5230\u66f4\u591a\u7684Python\u7684\u529f\u80fd\uff08\u6570\u636e\u7c7b\u578b\uff0c\u51fd\u6570\uff0c\u6a21\u5757\uff0c\u7c7b\u7b49\u7b49\uff09\u65f6\u53ef\u80fd\u78b0\u5230\u7684\u95ee\u9898\u4e86\u3002\u7531\u4e8e\u7bc7\u5e45\u6709\u9650\uff0c\u8fd9\u91cc\u5c3d\u91cf\u7cbe\u7b80\uff0c\u5c24\u5176\u662f\u5bf9\u4e00\u4e9b\u9ad8\u7ea7\u7684\u6982\u5ff5\u3002\u8981\u60f3\u4e86\u89e3\u66f4\u591a\u7684\u7ec6\u8282\uff0c\u656c\u8bf7\u9605\u8bfbLearning Python, 2nd Edition\u7684\u9017\u5c0f\u8d34\u58eb\u5730\u4ee5\u53ca\u9017Gotchas\u5730\u7ae0\u8282\u3002

\u6253\u5f00\u6587\u4ef6\u7684\u8c03\u7528\u4e0d\u4f7f\u7528\u6a21\u5757\u641c\u7d22\u8def\u5f84
\u5f53\u4f60\u5728Python\u4e2d\u8c03\u7528open()\u6765\u8bbf\u95ee\u4e00\u4e2a\u5916\u90e8\u7684\u6587\u4ef6\u65f6\uff0cPython\u4e0d\u4f1a\u4f7f\u7528\u6a21\u5757\u641c\u7d22\u8def\u5f84\u6765\u5b9a\u4f4d\u8fd9\u4e2a\u76ee\u6807\u6587\u4ef6\u3002\u5b83\u4f1a\u4f7f\u7528\u4f60\u63d0\u4f9b\u7684\u7edd\u5bf9\u8def\u5f84\uff0c\u6216\u8005\u5047\u5b9a\u8fd9\u4e2a\u6587\u4ef6\u662f\u5728\u5f53\u524d\u5de5\u4f5c\u76ee\u5f55\u4e2d\u3002\u6a21\u5757\u641c\u7d22\u8def\u5f84\u4ec5\u4ec5\u4e3a\u6a21\u5757\u52a0\u8f7d\u670d\u52a1\u7684\u3002
\u4e0d\u540c\u7684\u7c7b\u578b\u5bf9\u5e94\u7684\u65b9\u6cd5\u4e5f\u4e0d\u540c
\u5217\u8868\u7684\u65b9\u6cd5\u662f\u4e0d\u80fd\u7528\u5728\u5b57\u7b26\u4e32\u4e0a\u7684\uff0c\u53cd\u4e4b\u4ea6\u7136\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u65b9\u6cd5\u7684\u8c03\u7528\u662f\u548c\u6570\u636e\u7c7b\u578b\u6709\u5173\u7684\uff0c\u4f46\u662f\u5185\u90e8\u51fd\u6570\u901a\u5e38\u5728\u5f88\u591a\u7c7b\u578b\u4e0a\u90fd\u53ef\u4ee5\u4f7f\u7528\u3002\u4e3e\u4e2a\u4f8b\u5b50\u6765\u8bf4\uff0c\u5217\u8868\u7684reverse\u65b9\u6cd5\u4ec5\u4ec5\u5bf9\u5217\u8868\u6709\u7528\uff0c\u4f46\u662flen\u51fd\u6570\u5bf9\u4efb\u4f55\u5177\u6709\u957f\u5ea6\u7684\u5bf9\u8c61\u90fd\u9002\u7528
\u4e0d\u80fd\u76f4\u63a5\u6539\u53d8\u4e0d\u53ef\u53d8\u6570\u636e\u7c7b\u578b
\u8bb0\u4f4f\u4f60\u6ca1\u6cd5\u76f4\u63a5\u7684\u6539\u53d8\u4e00\u4e2a\u4e0d\u53ef\u53d8\u7684\u5bf9\u8c61\uff08\u4f8b\u5982\uff0c\u5143\u7ec4\uff0c\u5b57\u7b26\u4e32\uff09\uff1a

T = (1, 2, 3)
T[2] = 4 # \u9519\u8bef

\u7528\u5207\u7247\uff0c\u8054\u63a5\u7b49\u6784\u5efa\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\uff0c\u5e76\u6839\u636e\u9700\u6c42\u5c06\u539f\u6765\u53d8\u91cf\u7684\u503c\u8d4b\u7ed9\u5b83\u3002\u56e0\u4e3aPython\u4f1a\u81ea\u52a8\u56de\u6536\u6ca1\u6709\u7528\u7684\u5185\u5b58\uff0c\u56e0\u6b64\u8fd9\u6ca1\u6709\u770b\u8d77\u6765\u90a3\u4e48\u6d6a\u8d39\uff1a

T = T[:2] + (4,) # \u6ca1\u95ee\u9898\u4e86: T \u53d8\u6210\u4e86 (1, 2, 4)

\u4f7f\u7528\u7b80\u5355\u7684for\u5faa\u73af\u800c\u4e0d\u662fwhile\u6216\u8005range
\u5f53\u4f60\u8981\u4ece\u5de6\u5230\u53f3\u904d\u5386\u4e00\u4e2a\u6709\u5e8f\u7684\u5bf9\u8c61\u7684\u6240\u6709\u5143\u7d20\u65f6\uff0c\u7528\u7b80\u5355\u7684for\u5faa\u73af\uff08\u4f8b\u5982\uff0cfor x in seq:\uff09\u76f8\u6bd4\u4e8e\u57fa\u4e8ewhile-\u6216\u8005range-\u7684\u8ba1\u6570\u5faa\u73af\u800c\u8a00\u4f1a\u66f4\u5bb9\u6613\u5199\uff0c\u901a\u5e38\u8fd0\u884c\u8d77\u6765\u4e5f\u66f4\u5feb\u3002\u9664\u975e\u4f60\u4e00\u5b9a\u9700\u8981\uff0c\u5c3d\u91cf\u907f\u514d\u5728\u4e00\u4e2afor\u5faa\u73af\u91cc\u4f7f\u7528range\uff1a\u8ba9Python\u6765\u66ff\u4f60\u89e3\u51b3\u6807\u53f7\u7684\u95ee\u9898\u3002\u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u4e2d\u4e09\u4e2a\u5faa\u73af\u7ed3\u6784\u90fd\u6ca1\u6709\u95ee\u9898\uff0c\u4f46\u662f\u7b2c\u4e00\u4e2a\u901a\u5e38\u6765\u8bf4\u66f4\u597d\uff1b\u5728Python\u91cc\uff0c\u7b80\u5355\u81f3\u4e0a\u3002

S = "lumberjack"

for c in S: print c # \u6700\u7b80\u5355

for i in range(len(S)): print S[i] # \u592a\u591a\u4e86

i = 0 # \u592a\u591a\u4e86
while i < len(S): print S[i]; i += 1

\u4e0d\u8981\u8bd5\u56fe\u4ece\u90a3\u4e9b\u4f1a\u6539\u53d8\u5bf9\u8c61\u7684\u51fd\u6570\u5f97\u5230\u7ed3\u679c
\u8bf8\u5982\u50cf\u65b9\u6cd5list.append()\u548clist.sort()\u4e00\u7c7b\u7684\u76f4\u63a5\u6539\u53d8\u64cd\u4f5c\u4f1a\u6539\u53d8\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4f46\u4e0d\u4f1a\u5c06\u5b83\u4eec\u6539\u53d8\u7684\u5bf9\u8c61\u8fd4\u56de\u51fa\u6765\uff08\u5b83\u4eec\u4f1a\u8fd4\u56deNone\uff09\uff1b\u6b63\u786e\u7684\u505a\u6cd5\u662f\u76f4\u63a5\u8c03\u7528\u5b83\u4eec\u800c\u4e0d\u8981\u5c06\u7ed3\u679c\u8d4b\u503c\u3002\u7ecf\u5e38\u4f1a\u770b\u89c1\u521d\u5b66\u8005\u4f1a\u5199\u8bf8\u5982\u6b64\u7c7b\u7684\u4ee3\u7801\uff1a

mylist = mylist.append(X)

\u76ee\u7684\u662f\u8981\u5f97\u5230append\u7684\u7ed3\u679c\uff0c\u4f46\u662f\u4e8b\u5b9e\u4e0a\u8fd9\u6837\u505a\u4f1a\u5c06None\u8d4b\u503c\u7ed9mylist\uff0c\u800c\u4e0d\u662f\u6539\u53d8\u540e\u7684\u5217\u8868\u3002\u66f4\u52a0\u7279\u522b\u7684\u4e00\u4e2a\u4f8b\u5b50\u662f\u60f3\u901a\u8fc7\u7528\u6392\u5e8f\u540e\u7684\u952e\u503c\u6765\u904d\u5386\u4e00\u4e2a\u5b57\u5178\u91cc\u7684\u5404\u4e2a\u5143\u7d20\uff0c\u8bf7\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\uff1a

D = {...}
for k in D.keys().sort(): print D[k]

\u5dee\u4e00\u70b9\u513f\u5c31\u6210\u529f\u4e86\u2014\u2014keys\u65b9\u6cd5\u4f1a\u521b\u5efa\u4e00\u4e2akeys\u7684\u5217\u8868\uff0c\u7136\u540e\u7528sort\u65b9\u6cd5\u6765\u5c06\u8fd9\u4e2a\u5217\u8868\u6392\u5e8f\u2014\u2014\u4f46\u662f\u56e0\u4e3asort\u65b9\u6cd5\u4f1a\u8fd4\u56deNone\uff0c\u8fd9\u4e2a\u5faa\u73af\u4f1a\u5931\u8d25\uff0c\u56e0\u4e3a\u5b83\u5b9e\u9645\u4e0a\u662f\u8981\u904d\u5386None\uff08\u8fd9\u53ef\u4e0d\u662f\u4e00\u4e2a\u5e8f\u5217\uff09\u3002\u8981\u6539\u6b63\u8fd9\u6bb5\u4ee3\u7801\uff0c\u5c06\u65b9\u6cd5\u7684\u8c03\u7528\u5206\u79bb\u51fa\u6765\uff0c\u653e\u5728\u4e0d\u540c\u7684\u8bed\u53e5\u4e2d\uff0c\u5982\u4e0b\uff1a

Ks = D.keys()
Ks.sort()
for k in Ks: print D[k]

\u53ea\u6709\u5728\u6570\u5b57\u7c7b\u578b\u4e2d\u624d\u5b58\u5728\u7c7b\u578b\u8f6c\u6362
\u5728Python\u4e2d\uff0c\u4e00\u4e2a\u8bf8\u5982123+3.145\u7684\u8868\u8fbe\u5f0f\u662f\u53ef\u4ee5\u5de5\u4f5c\u7684\u2014\u2014\u5b83\u4f1a\u81ea\u52a8\u5c06\u6574\u6570\u578b\u8f6c\u6362\u4e3a\u6d6e\u70b9\u578b\uff0c\u7136\u540e\u7528\u6d6e\u70b9\u8fd0\u7b97\u3002\u4f46\u662f\u4e0b\u9762\u7684\u4ee3\u7801\u5c31\u4f1a\u51fa\u9519\u4e86\uff1a

S = "42"
I = 1
X = S + I # \u7c7b\u578b\u9519\u8bef

\u8fd9\u540c\u6837\u4e5f\u662f\u6709\u610f\u800c\u4e3a\u7684\uff0c\u56e0\u4e3a\u8fd9\u662f\u4e0d\u660e\u786e\u7684\uff1a\u7a76\u7adf\u662f\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u6570\u5b57\uff08\u8fdb\u884c\u76f8\u52a0\uff09\u5462\uff0c\u8fd8\u662f\u5c06\u6570\u5b57\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\uff08\u8fdb\u884c\u8054\u63a5\uff09\u5462\u770b\u5728Python\u4e2d\uff0c\u6211\u4eec\u8ba4\u4e3a\u9017\u660e\u786e\u6bd4\u542b\u7cca\u597d\u5730\uff08\u5373\uff0cEIBTI\uff08Explicit is better than implicit\uff09\uff09\uff0c\u56e0\u6b64\u4f60\u5f97\u624b\u52a8\u8f6c\u6362\u7c7b\u578b\uff1a

X = int(S) + I # \u505a\u52a0\u6cd5: 43
X = S + str(I) # \u5b57\u7b26\u4e32\u8054\u63a5: "421"

\u5faa\u73af\u7684\u6570\u636e\u7ed3\u6784\u4f1a\u5bfc\u81f4\u5faa\u73af
\u5c3d\u7ba1\u8fd9\u5728\u5b9e\u9645\u60c5\u51b5\u4e2d\u5f88\u5c11\u89c1\uff0c\u4f46\u662f\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u7684\u96c6\u5408\u5305\u542b\u4e86\u5230\u5b83\u81ea\u5df1\u7684\u5f15\u7528\uff0c\u8fd9\u88ab\u79f0\u4e3a\u5faa\u73af\u5bf9\u8c61\uff08cyclic object\uff09\u3002\u5982\u679c\u5728\u4e00\u4e2a\u5bf9\u8c61\u4e2d\u53d1\u73b0\u4e00\u4e2a\u5faa\u73af\uff0cPython\u4f1a\u8f93\u51fa\u4e00\u4e2a[\u2026]\uff0c\u4ee5\u907f\u514d\u5728\u65e0\u9650\u5faa\u73af\u4e2d\u5361\u4f4f\uff1a

>>> L = ['grail'] # \u5728 L\u4e2d\u53c8\u5f15\u7528L\u81ea\u8eab\u4f1a
>>> L.append(L) # \u5728\u5bf9\u8c61\u4e2d\u521b\u9020\u4e00\u4e2a\u5faa\u73af
>>> L
['grail', [...]]

\u9664\u4e86\u77e5\u9053\u8fd9\u4e09\u4e2a\u70b9\u5728\u5bf9\u8c61\u4e2d\u8868\u793a\u5faa\u73af\u4ee5\u5916\uff0c\u8fd9\u4e2a\u4f8b\u5b50\u4e5f\u662f\u5f88\u503c\u5f97\u501f\u9274\u7684\u3002\u56e0\u4e3a\u4f60\u53ef\u80fd\u65e0\u610f\u95f4\u5728\u4f60\u7684\u4ee3\u7801\u4e2d\u51fa\u73b0\u8fd9\u6837\u7684\u5faa\u73af\u7684\u7ed3\u6784\u800c\u5bfc\u81f4\u4f60\u7684\u4ee3\u7801\u51fa\u9519\u3002\u5982\u679c\u6709\u5fc5\u8981\u7684\u8bdd\uff0c\u7ef4\u62a4\u4e00\u4e2a\u5217\u8868\u6216\u8005\u5b57\u5178\u6765\u8868\u793a\u5df2\u7ecf\u8bbf\u95ee\u8fc7\u7684\u5bf9\u8c61\uff0c\u7136\u540e\u901a\u8fc7\u68c0\u67e5\u5b83\u6765\u786e\u8ba4\u4f60\u662f\u5426\u78b0\u5230\u4e86\u5faa\u73af\u3002
\u8d4b\u503c\u8bed\u53e5\u4e0d\u4f1a\u521b\u5efa\u5bf9\u8c61\u7684\u526f\u672c\uff0c\u4ec5\u4ec5\u521b\u5efa\u5f15\u7528
\u8fd9\u662fPython\u7684\u4e00\u4e2a\u6838\u5fc3\u7406\u5ff5\uff0c\u6709\u65f6\u5019\u5f53\u884c\u4e3a\u4e0d\u5bf9\u65f6\u4f1a\u5e26\u6765\u9519\u8bef\u3002\u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u4e2d\uff0c\u4e00\u4e2a\u5217\u8868\u5bf9\u8c61\u88ab\u8d4b\u7ed9\u4e86\u540d\u4e3aL\u7684\u53d8\u91cf\uff0c\u7136\u540eL\u53c8\u5728\u5217\u8868M\u4e2d\u88ab\u5f15\u7528\u3002\u5185\u90e8\u6539\u53d8L\u7684\u8bdd\uff0c\u540c\u65f6\u4e5f\u4f1a\u6539\u53d8M\u6240\u5f15\u7528\u7684\u5bf9\u8c61\uff0c\u56e0\u4e3a\u5b83\u4eec\u4fe9\u90fd\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002

>>> L = [1, 2, 3] # \u5171\u7528\u7684\u5217\u8868\u5bf9\u8c61
>>> M = ['X', L, 'Y'] # \u5d4c\u5165\u4e00\u4e2a\u5230L\u7684\u5f15\u7528
>>> M
['X', [1, 2, 3], 'Y']

>>> L[1] = 0 # \u4e5f\u6539\u53d8\u4e86M
>>> M
['X', [1, 0, 3], 'Y']

\u901a\u5e38\u60c5\u51b5\u4e0b\u53ea\u6709\u5728\u7a0d\u5927\u4e00\u70b9\u7684\u7a0b\u5e8f\u91cc\u8fd9\u5c31\u663e\u5f97\u5f88\u91cd\u8981\u4e86\uff0c\u800c\u4e14\u8fd9\u4e9b\u5171\u7528\u7684\u5f15\u7528\u901a\u5e38\u786e\u5b9e\u662f\u4f60\u9700\u8981\u7684\u3002\u5982\u679c\u4e0d\u662f\u7684\u8bdd\uff0c\u4f60\u53ef\u4ee5\u660e\u786e\u7684\u7ed9\u4ed6\u4eec\u521b\u5efa\u4e00\u4e2a\u526f\u672c\u6765\u907f\u514d\u5171\u7528\u7684\u5f15\u7528\uff1b\u5bf9\u4e8e\u5217\u8868\u6765\u8bf4\uff0c\u4f60\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528\u4e00\u4e2a\u7a7a\u5217\u8868\u7684\u5207\u7247\u6765\u521b\u5efa\u4e00\u4e2a\u9876\u5c42\u7684\u526f\u672c\uff1a

>>> L = [1, 2, 3]
>>> M = ['X', L[:], 'Y'] # \u5d4c\u5165\u4e00\u4e2aL\u7684\u526f\u672c

>>> L[1] = 0 # \u4ec5\u4ec5\u6539\u53d8\u4e86L\uff0c\u4f46\u662f\u4e0d\u5f71\u54cdM
>>> L
[1, 0, 3]
>>> M
['X', [1, 2, 3], 'Y']

\u5207\u7247\u7684\u8303\u56f4\u8d77\u59cb\u4ece\u9ed8\u8ba4\u76840\u5230\u88ab\u5207\u7247\u7684\u5e8f\u5217\u7684\u6700\u5927\u957f\u5ea6\u3002\u5982\u679c\u4e24\u8005\u90fd\u7701\u7565\u6389\u4e86\uff0c\u90a3\u4e48\u5207\u7247\u4f1a\u62bd\u53d6\u8be5\u5e8f\u5217\u4e2d\u7684\u6240\u6709\u5143\u7d20\uff0c\u5e76\u521b\u9020\u4e00\u4e2a\u9876\u5c42\u7684\u526f\u672c\uff08\u4e00\u4e2a\u65b0\u7684\uff0c\u4e0d\u88ab\u516c\u7528\u7684\u5bf9\u8c61\uff09\u3002\u5bf9\u4e8e\u5b57\u5178\u6765\u8bf4\uff0c\u4f7f\u7528\u5b57\u5178\u7684dict.copy()\u65b9\u6cd5\u3002
\u9759\u6001\u8bc6\u522b\u672c\u5730\u57df\u7684\u53d8\u91cf\u540d
Python\u9ed8\u8ba4\u5c06\u4e00\u4e2a\u51fd\u6570\u4e2d\u8d4b\u503c\u7684\u53d8\u91cf\u540d\u89c6\u4f5c\u662f\u672c\u5730\u57df\u7684\uff0c\u5b83\u4eec\u5b58\u5728\u4e8e\u8be5\u51fd\u6570\u7684\u4f5c\u7528\u57df\u4e2d\u5e76\u4e14\u4ec5\u4ec5\u5728\u51fd\u6570\u8fd0\u884c\u7684\u65f6\u5019\u624d\u5b58\u5728\u3002\u4ece\u6280\u672f\u4e0a\u8bb2\uff0cPython\u662f\u5728\u7f16\u8bd1def\u4ee3\u7801\u65f6\uff0c\u53bb\u9759\u6001\u7684\u8bc6\u522b\u672c\u5730\u53d8\u91cf\uff0c\u800c\u4e0d\u662f\u5728\u8fd0\u884c\u65f6\u78b0\u5230\u8d4b\u503c\u7684\u65f6\u5019\u624d\u8bc6\u522b\u5230\u7684\u3002\u5982\u679c\u4e0d\u7406\u89e3\u8fd9\u70b9\u7684\u8bdd\uff0c\u4f1a\u5f15\u8d77\u4eba\u4eec\u7684\u8bef\u89e3\u3002\u6bd4\u5982\uff0c\u770b\u770b\u4e0b\u9762\u7684\u4f8b\u5b50\uff0c\u5f53\u4f60\u5728\u4e00\u4e2a\u5f15\u7528\u4e4b\u540e\u7ed9\u4e00\u4e2a\u53d8\u91cf\u8d4b\u503c\u4f1a\u600e\u4e48\u6837\uff1a

>>> X = 99
>>> def func():
... print X # \u8fd9\u4e2a\u65f6\u5019\u8fd8\u4e0d\u5b58\u5728
... X = 88 # \u5728\u6574\u4e2adef\u4e2d\u5c06X\u89c6\u4f5c\u672c\u5730\u53d8\u91cf
...
>>> func( ) # \u51fa\u9519\u4e86\uff01

\u4f60\u4f1a\u5f97\u5230\u4e00\u4e2a\u9017\u672a\u5b9a\u4e49\u53d8\u91cf\u540d\u5730\u7684\u9519\u8bef\uff0c\u4f46\u662f\u5176\u539f\u56e0\u662f\u5f88\u5fae\u5999\u7684\u3002\u5f53\u7f16\u8bd1\u8fd9\u5219\u4ee3\u7801\u65f6\uff0cPython\u78b0\u5230\u7ed9X\u8d4b\u503c\u7684\u8bed\u53e5\u65f6\u8ba4\u4e3a\u5728\u8fd9\u4e2a\u51fd\u6570\u4e2d\u7684\u4efb\u4f55\u5730\u65b9X\u4f1a\u88ab\u89c6\u4f5c\u4e00\u4e2a\u672c\u5730\u53d8\u91cf\u540d\u3002\u4f46\u662f\u4e4b\u540e\u5f53\u771f\u6b63\u8fd0\u884c\u8fd9\u4e2a\u51fd\u6570\u65f6\uff0c\u6267\u884cprint\u8bed\u53e5\u7684\u65f6\u5019\uff0c\u8d4b\u503c\u8bed\u53e5\u8fd8\u6ca1\u6709\u53d1\u751f\uff0c\u8fd9\u6837Python\u4fbf\u4f1a\u62a5\u544a\u4e00\u4e2a\u9017\u672a\u5b9a\u4e49\u53d8\u91cf\u540d\u5730\u7684\u9519\u8bef\u3002
\u4e8b\u5b9e\u4e0a\uff0c\u4e4b\u524d\u7684\u8fd9\u4e2a\u4f8b\u5b50\u60f3\u8981\u505a\u7684\u4e8b\u60c5\u662f\u5f88\u6a21\u7cca\u7684\uff1a\u4f60\u662f\u60f3\u8981\u5148\u8f93\u51fa\u90a3\u4e2a\u5168\u5c40\u7684X\uff0c\u7136\u540e\u521b\u5efa\u4e00\u4e2a\u672c\u5730\u7684X\u5462\uff0c\u8fd8\u662f\u8bf4\u8fd9\u662f\u4e2a\u7a0b\u5e8f\u7684\u9519\u8bef\u770b\u5982\u679c\u4f60\u771f\u7684\u662f\u60f3\u8981\u8f93\u51fa\u8fd9\u4e2a\u5168\u5c40\u7684X\uff0c\u4f60\u9700\u8981\u5c06\u5b83\u5728\u4e00\u4e2a\u5168\u5c40\u8bed\u53e5\u4e2d\u58f0\u660e\u5b83\uff0c\u6216\u8005\u901a\u8fc7\u5305\u7edc\u6a21\u5757\u7684\u540d\u5b57\u6765\u5f15\u7528\u5b83\u3002
\u9ed8\u8ba4\u53c2\u6570\u548c\u53ef\u53d8\u5bf9\u8c61
\u5728\u6267\u884cdef\u8bed\u53e5\u65f6\uff0c\u9ed8\u8ba4\u53c2\u6570\u7684\u503c\u53ea\u88ab\u89e3\u6790\u5e76\u4fdd\u5b58\u4e00\u6b21\uff0c\u800c\u4e0d\u662f\u6bcf\u6b21\u5728\u8c03\u7528\u51fd\u6570\u7684\u65f6\u5019\u3002\u8fd9\u901a\u5e38\u662f\u4f60\u60f3\u8981\u7684\u90a3\u6837\uff0c\u4f46\u662f\u56e0\u4e3a\u9ed8\u8ba4\u503c\u9700\u8981\u5728\u6bcf\u6b21\u8c03\u7528\u65f6\u90fd\u4fdd\u6301\u540c\u6837\u5bf9\u8c61\uff0c\u4f60\u5728\u8bd5\u56fe\u6539\u53d8\u53ef\u53d8\u7684\u9ed8\u8ba4\u503c\uff08mutable defaults\uff09\u7684\u65f6\u5019\u53ef\u8981\u5c0f\u5fc3\u4e86\u3002\u4f8b\u5982\uff0c\u4e0b\u9762\u7684\u51fd\u6570\u4e2d\u4f7f\u7528\u4e00\u4e2a\u7a7a\u7684\u5217\u8868\u4f5c\u4e3a\u9ed8\u8ba4\u503c\uff0c\u7136\u540e\u5728\u4e4b\u540e\u6bcf\u4e00\u6b21\u51fd\u6570\u8c03\u7528\u7684\u65f6\u5019\u6539\u53d8\u5b83\u7684\u503c\uff1a

>>> def saver(x=[]): # \u4fdd\u5b58\u4e00\u4e2a\u5217\u8868\u5bf9\u8c61
... x.append(1) # \u5e76\u6bcf\u6b21\u8c03\u7528\u7684\u65f6\u5019
... print x # \u6539\u53d8\u5b83\u7684\u503c
...
>>> saver([2]) # \u672a\u4f7f\u7528\u9ed8\u8ba4\u503c
[2, 1]
>>> saver() # \u4f7f\u7528\u9ed8\u8ba4\u503c
[1]
>>> saver() # \u6bcf\u6b21\u8c03\u7528\u90fd\u4f1a\u589e\u52a0\uff01
[1, 1]
>>> saver()
[1, 1, 1]

\u6709\u7684\u4eba\u5c06\u8fd9\u4e2a\u89c6\u4f5cPython\u7684\u4e00\u4e2a\u7279\u70b9\u2014\u2014\u56e0\u4e3a\u53ef\u53d8\u7684\u9ed8\u8ba4\u53c2\u6570\u5728\u6bcf\u6b21\u51fd\u6570\u8c03\u7528\u65f6\u4fdd\u6301\u4e86\u5b83\u4eec\u7684\u72b6\u6001\uff0c\u5b83\u4eec\u80fd\u63d0\u4f9b\u50cfC\u8bed\u8a00\u4e2d\u9759\u6001\u672c\u5730\u51fd\u6570\u53d8\u91cf\u7684\u7c7b\u4f3c\u7684\u4e00\u4e9b\u529f\u80fd\u3002\u4f46\u662f\uff0c\u5f53\u4f60\u7b2c\u4e00\u6b21\u78b0\u5230\u5b83\u65f6\u4f1a\u89c9\u5f97\u8fd9\u5f88\u5947\u602a\uff0c\u5e76\u4e14\u5728Python\u4e2d\u6709\u66f4\u52a0\u7b80\u5355\u7684\u529e\u6cd5\u6765\u5728\u4e0d\u540c\u7684\u8c03\u7528\u4e4b\u95f4\u4fdd\u5b58\u72b6\u6001\uff08\u6bd4\u5982\u8bf4\u7c7b\uff09\u3002
\u8981\u6446\u8131\u8fd9\u6837\u7684\u884c\u4e3a\uff0c\u5728\u51fd\u6570\u5f00\u59cb\u7684\u5730\u65b9\u7528\u5207\u7247\u6216\u8005\u65b9\u6cd5\u6765\u521b\u5efa\u9ed8\u8ba4\u53c2\u6570\u7684\u526f\u672c\uff0c\u6216\u8005\u5c06\u9ed8\u8ba4\u503c\u7684\u8868\u8fbe\u5f0f\u79fb\u5230\u51fd\u6570\u91cc\u9762\uff1b\u53ea\u8981\u6bcf\u6b21\u51fd\u6570\u8c03\u7528\u65f6\u8fd9\u4e9b\u503c\u5728\u51fd\u6570\u91cc\uff0c\u5c31\u4f1a\u6bcf\u6b21\u90fd\u5f97\u5230\u4e00\u4e2a\u65b0\u7684\u5bf9\u8c61\uff1a

>>> def saver(x=None):

... if x is None: x = [] # \u6ca1\u6709\u4f20\u5165\u53c2\u6570\u770b
... x.append(1) # \u6539\u53d8\u65b0\u7684\u5217\u8868
... print x
...
>>> saver([2]) # \u6ca1\u6709\u4f7f\u7528\u9ed8\u8ba4\u503c
[2, 1]
>>> saver() # \u8fd9\u6b21\u4e0d\u4f1a\u53d8\u4e86
[1]
>>> saver()
[1]

\u5176\u4ed6\u5e38\u89c1\u7684\u7f16\u7a0b\u9677\u9631
\u4e0b\u9762\u5217\u4e3e\u4e86\u5176\u4ed6\u7684\u4e00\u4e9b\u5728\u8fd9\u91cc\u6ca1\u6cd5\u8be6\u8ff0\u7684\u9677\u9631\uff1a
\u5728\u9876\u5c42\u6587\u4ef6\u4e2d\u8bed\u53e5\u7684\u987a\u5e8f\u662f\u6709\u8bb2\u7a76\u7684\uff1a\u56e0\u4e3a\u8fd0\u884c\u6216\u8005\u52a0\u8f7d\u4e00\u4e2a\u6587\u4ef6\u4f1a\u4ece\u4e0a\u5230\u4e0b\u8fd0\u884c\u5b83\u7684\u8bed\u53e5\uff0c\u6240\u4ee5\u8bf7\u786e\u4fdd\u5c06\u4f60\u672a\u5d4c\u5957\u7684\u51fd\u6570\u8c03\u7528\u6216\u8005\u7c7b\u7684\u8c03\u7528\u653e\u5728\u51fd\u6570\u6216\u8005\u7c7b\u7684\u5b9a\u4e49\u4e4b\u540e\u3002
reload\u4e0d\u5f71\u54cd\u7528from\u52a0\u8f7d\u7684\u540d\u5b57\uff1areload\u6700\u597d\u548cimport\u8bed\u53e5\u4e00\u8d77\u4f7f\u7528\u3002\u5982\u679c\u4f60\u4f7f\u7528from\u8bed\u53e5\uff0c\u8bb0\u5f97\u5728reload\u4e4b\u540e\u91cd\u65b0\u8fd0\u884c\u4e00\u904dfrom\uff0c\u5426\u5219\u4f60\u4ecd\u7136\u4f7f\u7528\u4e4b\u524d\u8001\u7684\u540d\u5b57\u3002
\u5728\u591a\u91cd\u7ee7\u627f\u4e2d\u6df7\u5408\u7684\u987a\u5e8f\u662f\u6709\u8bb2\u7a76\u7684\uff1a\u8fd9\u662f\u56e0\u4e3a\u5bf9superclass\u7684\u641c\u7d22\u662f\u4ece\u5de6\u5230\u53f3\u7684\uff0c\u5728\u7c7b\u5b9a\u4e49\u7684\u5934\u90e8\uff0c\u5728\u591a\u91cdsuperclass\u4e2d\u5982\u679c\u51fa\u73b0\u91cd\u590d\u7684\u540d\u5b57\uff0c\u5219\u4ee5\u6700\u5de6\u8fb9\u7684\u7c7b\u540d\u4e3a\u51c6\u3002
\u5728try\u8bed\u53e5\u4e2d\u7a7a\u7684except\u5b50\u53e5\u53ef\u80fd\u4f1a\u6bd4\u4f60\u9884\u60f3\u7684\u6355\u6349\u5230\u66f4\u591a\u7684\u9519\u8bef\u3002\u5728try\u8bed\u53e5\u4e2d\u7a7a\u7684except\u5b50\u53e5\u8868\u793a\u6355\u6349\u6240\u6709\u7684\u9519\u8bef\uff0c\u5373\u4fbf\u662f\u771f\u6b63\u7684\u7a0b\u5e8f\u9519\u8bef\uff0c\u548csys.exit()\u8c03\u7528\uff0c\u4e5f\u4f1a\u88ab\u6355\u6349\u5230\u3002

\u5728\u64cd\u4f5c\u7cfb\u7edf\u63d0\u4f9b\u7684\u8c03\u7528\u4e2d\uff0c\u8fd4\u56de\u9519\u8bef\u7801\u975e\u5e38\u5e38\u89c1\u3002\u6bd4\u7528\u9519\u8bef\u7801\u6765\u8868\u793a\u662f\u5426\u51fa\u9519\u5341\u5206\u4e0d\u4fbf\uff0c\u56e0\u4e3a\u51fd\u6570\u672c\u8eab\u5e94\u8be5\u8fd4\u56de\u7684\u6b63\u5e38\u7ed3\u679c\u548c\u9519\u8bef\u7801\u6df7\u5728\u4e00\u8d77\uff0c\u9020\u6210\u8c03\u7528\u8005\u5fc5\u987b\u7528\u5927\u91cf\u7684\u4ee3\u7801\u6765\u5224\u65ad\u662f\u5426\u51fa\u9519

错误信息写的很清楚了，name "fab" is not defined ...
你都没有写fab这个函数，当然调用不到了。
你得把清单1里的 def fab(max) ... 这一段也得写出来。

扩展阅读：python闪一下就消失了 ... python运行暂停 继续 ... python run 不出来 ... python运行不了 显示警告 ... python代码不能执行怎么办 ... 学python最佳年龄 ... 代码没错但运行不出来 ... 学python有前途吗 ... python运行不出结果怎么办 ...