Python · lambda, Recursion & Built-in Functions

Your set can't be used as a dict key or placed inside another set. Which built-in fixes this?

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More in lambda, Recursion & Built-in Functions

A teammate wants a lambda that prints a value and returns it: lambda x: print(x); return x. Why won't this work?

You need to sort people by their age attribute. A colleague writes people.sort(lambda p: p.age). What's wrong?

What does this print? ``` funcs = [lambda: i for i in range(3)] print([f() for f in funcs]) ```

In a loop you build callbacks with lambda: x and they all end up using the last value of x. What's the standard fix?

What does this print? ``` def fac(n): if n > 1: return fac(n-1) * n return 1 print(fac(0)) ```

A deep recursive function on a big input dies with RecursionError: maximum recursion depth exceeded. Why, and what's the usual fix?

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