Unable to create a local function because “can’t capture dynamic environment in a fn item”

Functions in Rust don’t capture variables from the surrounding environment, period. A “local” function in Rust is really just a global function that isn’t globally visible; it can’t do anything more than any other global function. Instead, Rust has closures which are distinct from functions in that they do capture variables from their environment. That … Read more

Passing a function with multiple arguments to DataFrame.apply

It’s just the way you think it would be, apply accepts args and kwargs and passes them directly to some_func. df.apply(some_func, var1=’DOG’, axis=1) Or, df.apply(some_func, args=(‘DOG’, ), axis=1) 0 foo-x-DOG 1 bar-y-DOG dtype: object If for any reason that won’t work for your use case, then you can always fallback to using a lambda: df.apply(lambda … Read more

Check if two Python functions are equal

The one thing you could test for is code object equality: >>> x = lambda x: x >>> y = lambda y: y >>> x.__code__.co_code ‘|\x00\x00S’ >>> x.__code__.co_code == y.__code__.co_code True Here the bytecode for both functions is the same. You’ll perhaps need to verify more aspects of the code objects (constants and closures spring … Read more

What is first class function in Python

A first-class function is not a particular kind of function. All functions in Python are first-class functions. To say that functions are first-class in a certain programming language means that they can be passed around and manipulated similarly to how you would pass around and manipulate other kinds of objects (like integers or strings). You … Read more

Where should I prefer pass-by-reference or pass-by-value?

There are four main cases where you should use pass-by-reference over pass-by-value: If you are calling a function that needs to modify its arguments, use pass-by-reference or pass-by-pointer. Otherwise, you’ll get a copy of the argument. If you’re calling a function that needs to take a large object as a parameter, pass it by const … Read more

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