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Python, lambda, find minimum

I have foreach function which calls specified function on every element which it contains. I want to get minimum from thise elements but I have no idea how to write lambda or function or even a class that would manage that. Thanks for every help.

I use my foreach function like this:

o.foreach( lambda i: i.call() )

o.foreach( I.call )

I don't like to make a lists or other objects. I want to iterate trough it and find min.

I manage to write a class that do the think but there should be some better solution than that:

class Min:                                           
    def __init__(self,i):                        
        self.i = i                              
    def get_min(self):                               
        return self.i                                
    def set_val(self,o):                             
        if o.val < self.i: self.i = o.val

m = Min( xmin )
self.foreach( m.set_val )                            
xmin = m.get_min()

Ok, so I suppose that my .foreach method is non-python idea. I should do my Class iterable because all your solutions are based on lists and then everything will become easier.

In C# there would be no problem with lambda function like that, so I though that python is also that powerful.

Answer*

Okay, one thing you need to understand: `lambda` creates a function object for you.  But so does plain, ordinary `def`.  Look at this example:

    lst = range(10)
    
    print filter(lambda x: x % 2 == 0, lst)
    
    def is_even(x):
        return x % 2 == 0
    
    print filter(is_even, lst)

Both of these work.  They produce the same identical result.  `lambda` makes an un-named function object; `def` makes a named function object.  `filter()` doesn't care whether the function object has a name or not.

So, if your only problem with `lambda` is that you can't use `=` in a `lambda`, you can just make a function using `def`.


Now, that said, I don't suggest you use your `.foreach()` method to find a minimum value.  Instead, make your main object return a list of values, and simply call the Python `min()` function.

    lst = range(10)
    print min(lst)

EDIT: I agree that the answer that was accepted is better.  Rather than returning a list of values, it is better to define `__iter__()` and make the object iterable.

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Python, lambda, find minimum

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