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Is there a way to chain functions with multiple arguments?

For the moment I "chain" my operation in Python like this:

def createDirIfNecessary(directoryName):
    if not os.path.exists(directoryName):
        print 'Creating directory [%s]'% directoryName
        os.makedirs(directoryName)
    return directoryName

cakeName = 'lemonPie'
cookDate = '2011-01-04'

#yewww very ugly, big blob of function call ...
myDir = os.path.join(getDbDir('kitchenCupboardDir'),'cakes', cakeName)
file  = os.path.join(createDirIfNecessary(myDir), cookDate + '.gz')

For example, in R there is a very elegant way to proceed using a 'pipe' %>% operator (pipe operator also present in Haskell). The equivalent code is:

cakeName = 'lemonPie'
cookDate = '2011-01-04'

file = getDbDir('kitchenCupboardDir') %>%
         file.path('cakes', cakeName) %>%
         createDirIfNecessary %>%
         file.path(paste0(cookDate,'.gz'))

Here there are only 4 functions, there can be 6, 7 wich can be easily chained. I can't use R unfortunately and I wonder if there is a solution in python 2.7

It is quite related to this topic but with further arguments: Better way to call a chain of functions in python?

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Colonel Beauvel
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1 Answers1

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The fn package (see on GitHub has the >> operator, and many other nice things for functional programming. You can do functional programming in python, even if (see also this answer) it's not really the optimal way. Python can "chain" functions through methods:

file = getDbDir(...).makePath(...).createDir(...).getPath(...)

This is a way to chain operations.

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Timothée Poisot
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