Python函数的参数默认值,是在编译阶段就初始化的,并不是每调用一次函数都会重新初始化。 故:test1 和 test2 中data的地址一样的,append了 2 次,就出现了 2 个end 参考资料: 1、The Hitchhiker’s Guide to Python Python’s default arguments are evaluatedoncewhen the function is defined, not each time ...
Dangers of using mutable default arguments Another common pitfall with mutability lies with default function arguments. A mutable object used as a default argument in a function could lead to unexpected behavior. This is because Python evaluates default arguments when the function is defined, not each...
Python's default arguments are evaluated at definition as opposed to when the function is invoked. This leads to unexpected behavior, as mutations persist between calls. For a more detailed explanation, see The Hitchhiker's Guide to Python. Example def fnc(a, b={}): pass foo.py:2:14: ...
Passing mutable lists or dictionaries as default arguments to a function can have unforeseen consequences. Usually when a programmer uses a list or dictionary as the default argument to a function, the programmer wants the program to create a new list or dictionary every time that the function ...
分析代码中可能导致ValueError: mutable default错误的地方: 你需要检查transformers.training_args_seq2seq.Seq2SeqTrainingArguments类或其方法中的参数,看看是否有使用可变对象作为默认值的情况。识别transformers.training_args_seq2seq.Seq2SeqTrainingArguments类或函数中可能存在的可变默认值问题:...
evaluates default arguments as part of the function definition allocates one mutable list for every call of that function. 也就是说在python中每个函数只编译?一次,而且默认参数会作为函数的一部分,上述的l = []是一个可变对象,究竟什么是可变对象和不可变对象?
slimkrazy / python-google-places Public Notifications Fork 167 Star 494 Code Issues 34 Pull requests 10 Actions Projects Wiki Security Insights CommitMerge pull request #83 from beamerblvd/fix-mutable-default-args Browse files Fix the use of mutable default arguments...
And the short answer is to use immutable types as default arguments for functions. You could have used None, for instance:def increase_values(var1=None, value=0): if var1 is None: var1 = [1, 1] ... PythonOf course, the decision is always yours. Perhaps you would like to update...
Python's functions have a lot of "wait I didn't know that" features. Functions can define default argument values, functions can be called with keyword arguments, and functions can be written to accept any number of arguments. To track your progress on this Python Morsels topic trail, sign...
There are places in the code (usually rather old code) where mutable objects are assigned to default arguments (see for instance #87 (comment)). While this is a clear mistake and should be fixed, we are deferring this fix because: The ob...