local maximum in a list"python"

Python lists will grow to use available memory, so there is no "local maximum".

Can you give us some context?

If you mean "How do I find the largest value contained within a list" Then the answer would be:

max(MyList)

So in Python 2.6:

print max(MyList)

would print the largest value contained within the list.

well no i want to find a local maximum in a list of points like for example:

A = [1,4,9,2,10,4]

the local maximums in this list are 9 and 10 we define a local max point as :    pi-1 < pi and pi+1 < pi.

i want to know if a function already exists it may be faster than a for loop.

Whilst I can't answer absolutely (I don't know every function/method supplied by Python), I would be surprised to find an in-built function for this as it is not something that would be required often enough.

Try the following snippet.  I guess that there is not any built-in function for that in standard modules.  The functionality is too special for that.

The function can be easily improved to get generator that is capable to consume any sequence and return the values on the fly.

def localMaxLst(lstIn):

    if len(lstIn) == 0:
        return []        # no results from empty list
        
    lst = []             # init -- no results yet
    m = lstIn[0]         # the first element as the maximum...
    candidate = True     # ... candidate
    
    for elem in lstIn[1:]:   # through elements from the second one
        if elem > m:         
            m = elem         # better candidate
            candidate = True
        elif elem == m:      # if equal, local maximum was lost
            candidate = False
        elif elem < m:       # if lower then possible candidate to output
            if candidate:
                lst.append(m)
            m = elem           # start again...
            candidate = False  # being smaller it cannot be candidate
            
    if candidate:        # if the peak at the very end
        lst.append(m)    
    return lst
    
    
lst = [1, 4, 9, 2, 10, 4]
print lst, '-->', localMaxLst(lst)                

lst = [1, 4, 9, 9, 2, 10, 4, 11]
print lst, '-->', localMaxLst(lst)                

lst = [12, 1, 4, 9, 9, 2, 10, 4, 11]
print lst, '-->', localMaxLst(lst)

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Here is the generator solution that can consume the values on the fly.

loool thank you Pepr! it's great.
thank you so much.