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Repeating elements of a list n times

How do I repeat each element of a list n times and form a new list? For example:

x = [1,2,3,4]
n = 3

x1 = [1,1,1,2,2,2,3,3,3,4,4,4]

x * n doesn't work

for i in x[i]:
    x1 = n * x[i]

There must be a simple and smart way.

Answer*

For base Python 2.7:

        from itertools import repeat
        def expandGrid(**kwargs):
            # Input is a series of lists as named arguments
            # output is a dictionary defining each combination, preserving names
            #
            # lengths of each input list
            listLens = [len(e) for e in kwargs.itervalues()] 
            # multiply all list lengths together to get total number of combinations
            nCombos = reduce((lambda x, y: x * y), listLens) 
            iDict = {}
            nTimesRepEachValue=1 #initialize as repeating only once
            for key in kwargs.keys():
                nTimesRepList=nCombos/(len(kwargs[key])*nTimesRepEachValue)
                tempVals=[] #temporary list to store repeated
                for v in range(nTimesRepList):
                    indicesToAdd=reduce((lambda x,y: list(x)+list(y)),[repeat(x, nTimesRepEachValue) for x in kwargs[key]])
                    tempVals=tempVals+indicesToAdd
                iDict[key] = tempVals
                # Accumulating the number of times needed to repeat each value
                nTimesRepEachValue=len(kwargs[key])*nTimesRepEachValue
            return iDict

        #Example usage:
        expandedDict=expandGrid(letters=["a","b","c","d"],nums=[1,2,3],both=["v",3])

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Repeating elements of a list n times

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