Kernighans large earthquake problem: Difference between revisions

Or, if scale permits a file slurp and a parse retained for further processing, we can combine the parse and filter with a concatMap abstraction:

<lang python>from os.path import expanduser

from functools import (reduce)

import re

# main :: IO ()

def main():

xs = concatMap(

lambda x: (

lambda cs=cols(x): (

lambda n=float(cs[2]):

[cs] if 6 < n else []

)()

)()

)(

lines(readFile('~/data.txt'))

)

print (xs)

# GENERIC ABSTRACTIONS ----------------------------

# cols :: String -> String

def cols(s):

return re.split('\s+', s)

# concatMap :: (a -> [b]) -> [a] -> [b]

def concatMap(f):

return lambda xs: (

reduce(lambda a, b: a + b, map(f, xs), [])

)

# lines :: String -> [String]

def lines(s):

return s.splitlines()

# readFile :: FilePath -> IO String

def readFile(fp):

return open(expanduser(fp)).read()

# MAIN ---

main()</lang>

{{Out}}

<pre>

[['8/27/1883', 'Krakatoa', '8.8'], ['5/18/1980', 'MountStHelens', '7.6']]</pre>