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CS5035
Assignment 6

Author	Message
tvo54 Posts: 7	Posted 14:24 Mar 10, 2019 \| Any tips on how to create ['a' ..] in python?
rabbott Posts: 1649	Posted 14:28 Mar 10, 2019 \| Please elaborate on your question. What are you having trouble creating?
tvo54 Posts: 7	Posted 14:35 Mar 10, 2019 \| I know how to create a list containing a-z, but dont know how to create a list containing all the characters after that like {, (, \DEL, \128, \129, \130, Trying to figure out how to do this one: rlePropRoundTrip :: [Int] -> Bool rlePropRoundTrip ns = runLengthEncode xs == is where is = zip ['a' ..] $ map (\n -> n `mod` 100 + 1) ns xs = concatMap (\(i, n) -> replicate n i) is Last edited by tvo54 at 14:37 Mar 10, 2019.
jpatel77 Posts: 44	Posted 15:03 Mar 10, 2019 \| I would create a generator function that takes an argument that is string, converts that into `int` representation using `ord`, and then considering that as a starting point, would yield incremented value converted back into `char` using `chr`, indefinitely. You may then extract the indefinite sequence by calling `next` onto it. Last edited by jpatel77 at 15:04 Mar 10, 2019.
jpatel77 Posts: 44	Posted 15:48 Mar 10, 2019 \| I was wondering if we could wrap the existing `count` with required modification. `Toolz` lib turned out to be more useful than I thought. Here's how I tried to make our own wrapper: `>>> from toolz.curried import *` `>>> from itertools import count, islice` `>>> myCount = compose(map(chr), count, ord)` `>>> startFromA = myCount('A') >>> print(list(islice(startFromA, 5))) # first 5 from sequence` >>> `['A', 'B', 'C', 'D', 'E']` Edit: 'myCount' is more suitable than 'myRange' thus renamed it. Last edited by jpatel77 at 23:33 Mar 10, 2019.
tvo54 Posts: 7	Posted 15:55 Mar 10, 2019 \| Hm, for some reason I get 'int' object is not iterable when trying to run your code...
jpatel77 Posts: 44	Posted 16:01 Mar 10, 2019 \| Did you import the toolz? I used curried version of everything. Try importing the following: from toolz.curried import * from itertools import count, islice Edit: Just edited the code with required imports. Last edited by jpatel77 at 16:11 Mar 10, 2019.
rabbott Posts: 1649	Posted 16:06 Mar 10, 2019 \| To help me understand what you were after, I translated your original code into this. charNumPairs :: Integral n => [n] -> [(Char, n)] -- formerly is charNumPairs = zip ['a' ..] . map (\n -> n `mod` 100 + 1) repeatedCs :: [Int] -> [Char] -- formerly xs repeatedCs = concatMap (\(c, n) -> replicate n c) . charNumPairs runLengthEncode :: Eq a => [a] -> [(a, Int)] - copied from slide 50 of Amuse-Bouche runLengthEncode [] = [] runLengthEncode (x:xs) = nextGroup x 1 xs where nextGroup e n [] = [(e, n)] nextGroup e n (y:ys) \| e == y = nextGroup e (n + 1) ys \| otherwise = (e, n) : nextGroup y 1 ys rlePropRoundTrip :: [Int] -> Bool rlePropRoundTrip ns = runLengthEncode (repeatedCs ns) == charNumPairs ns This gives the result you want. > repeatedCs [1 .. 5] "aabbbccccdddddeeeeee" > rlePropRoundTrip [1 .. 5] True Not sure where to go from here. Jay's suggestion for generating letters sounds like a good approach. Last edited by rabbott at 16:13 Mar 10, 2019.
tvo54 Posts: 7	Posted 16:11 Mar 10, 2019 \| Ah, there we go. Okey, if i were to run this: something dwd = zip ['a' ..] $ map (\n -> n `mod` 100 + 1) dwd, where dwd = [1 up to 40], the output would be: [('a',2),('b',3),('c',4),('d',5),('e',6),('f',7),('g',8),('h',9),('i',10),('j',11),('k',12),('l',13),('m',14),('n',15),('o',16),('p',17),('q',18),('r',19),('s',20),('t',21),('u',22),('v',23),('w',24),('x',25),('y',26),('z',27),('{',28),('\|',29),('}',30),('~',31),('\DEL',32),('\128',33),('\129',34),('\130',35),('\131',36),('\132',37),('\133',38),('\134',39),('\135',40),('\136',41)] And if i choose range up to 40 with Jays code, it would print out: [('A', 2), ('B', 3), ('C', 4), ('D', 5), ('E', 6), ('F', 7), ('G', 8), ('H', 9), ('I', 10), ('J', 11), ('K', 12), ('L', 13), ('M', 14), ('N', 15), ('O', 16), ('P', 17), ('Q', 18), ('R', 19), ('S', 20), ('T', 21), ('U', 22), ('V', 23), ('W', 24), ('X', 25), ('Y', 26), ('Z', 27), ('[', 28), ('\\', 29), (']', 30), ('^', 31), ('_', 32), ('`', 33), ('a', 34), ('b', 35), ('c', 36), ('d', 37), ('e', 38), ('f', 39), ('g', 40), ('h', 41)] Should it matter what is in the first index of the tuples for rlePropRoundTrip to work? Last edited by tvo54 at 16:20 Mar 10, 2019.
rabbott Posts: 1649	Posted 16:18 Mar 10, 2019 \| Not sure what you are asking or where you got the result you show. What code are you running? Do you have actual input-output to show? This is what I get. > rlePropRoundTrip [1 .. 40] True > repeatedCs [1 .. 40] "aabbbccccdddddeeeeeefffffffgggggggghhhhhhhhhiiiiiiiiiijjjjjjjjjjjkkkkkkkkkkkklllllllllllllmmmmmmmmmmmmmmnnnnnnnnnnnnnnnoooooooooooooooopppppppppppppppppqqqqqqqqqqqqqqqqqqrrrrrrrrrrrrrrrrrrrsssssssssssssssssssstttttttttttttttttttttuuuuuuuuuuuuuuuuuuuuuuvvvvvvvvvvvvvvvvvvvvvvvwwwwwwwwwwwwwwwwwwwwwwwwxxxxxxxxxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyyyyyzzzzzzzzzzzzzzzzzzzzzzzzzzz{{{{{{{{{{{{{{{{{{{{{{{{{{{{\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|\|}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\DEL\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\128\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\129\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\130\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\131\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\132\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\133\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\134\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\135\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136\136" Last edited by rabbott at 16:23 Mar 10, 2019.
jpatel77 Posts: 44	Posted 16:26 Mar 10, 2019 \| tvo54 wrote: Ah, there we go. Okey, if i were to run this: something dwd = zip ['a' ..] $ map (\n -> n `mod` 100 + 1) dwd, where dwd = [1 up to 40], the output would be: [('a',2),('b',3),('c',4),('d',5),('e',6),('f',7),('g',8),('h',9),('i',10),('j',11),('k',12),('l',13),('m',14),('n',15),('o',16),('p',17),('q',18),('r',19),('s',20),('t',21),('u',22),('v',23),('w',24),('x',25),('y',26),('z',27),('{',28),('\|',29),('}',30),('~',31),('\DEL',32),('\128',33),('\129',34),('\130',35),('\131',36),('\132',37),('\133',38),('\134',39),('\135',40),('\136',41)] And if i choose range up to 40 with Jays code, it would print out: [('A', 2), ('B', 3), ('C', 4), ('D', 5), ('E', 6), ('F', 7), ('G', 8), ('H', 9), ('I', 10), ('J', 11), ('K', 12), ('L', 13), ('M', 14), ('N', 15), ('O', 16), ('P', 17), ('Q', 18), ('R', 19), ('S', 20), ('T', 21), ('U', 22), ('V', 23), ('W', 24), ('X', 25), ('Y', 26), ('Z', 27), ('[', 28), ('\\', 29), (']', 30), ('^', 31), ('_', 32), ('`', 33), ('a', 34), ('b', 35), ('c', 36), ('d', 37), ('e', 38), ('f', 39), ('g', 40), ('h', 41)] Should it matter what is in the first index of the tuples for rlePropRoundTrip to work? Are you sure you did ~~myRange('a')~~ myCount('a') and not ~~myRange('A')~~ myCount('A')? ~~myRange('a')~~ myCount('a') generates this seq on my machine: ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '\|', '}', '~', '\x7f', '\x80', '\x81', '\x82', '\x83', '\x84', '\x85', '\x86', '\x87', '\x88'] Which seems almost exactly like what you asked for, except for the later part where I believe it shows hex numbers instead of decimals. Last edited by jpatel77 at 23:35 Mar 10, 2019.
tvo54 Posts: 7	Posted 16:39 Mar 10, 2019 \| Ah, yeh it worked with myRange('a')!!! I was just confused by the hex. Okey, everything is clear now. Thanks Jay and Dr. Abbott.