Interleave blocks, or make object out of two blocks (field names and values) - object

Instead of creating objects by writing:
obj: object [
name: "Fork"
id: 1020
]
I'd like to write something like...
obj: something-or-another [name id] ["Fork" 1020]
...and get the same result. An ideal solution would also permit:
obj: something-or-another [name: id:] ["Fork" 1020]
Easy enough to write a something-or-another, but does this fit something already "in the box"?

I don't believe there's a baked-in way to do this. Not difficult though:
func [words values][
set words: context append map-each word words [to set-word! word] none values
words
]
I suppose I could break this down a little:
func [
"Creates an Object From a Block of Words, Assigns Values"
words [block!] "Words used to create object"
values "Value(s) to assign"
][
words: map-each word words [to set-word! word] ; The requisite set-words
append words none ; Initial value for all words
words: context words ; Create our object
set words values ; Assigns our value(s) to the object
words ; returns the object
]
You might employ a different method to interleave blocks, such as:
func [words [block!] values [block!]][
collect [
repeat index max length? words length? values [
keep words/:index
keep values/:index
]
]
]

Here's something that requires at least Rebol 3:
func [
"Create an object based on some words and values."
words [any-word! block!] "Word or block of words"
values [any-type!] "Value or block of values"
/local object
][
object: make object! either block? words [length? words] [1]
set bind/copy/new :words object :values
object
]
If you want to also allow setting unset values, try this:
func [
"Create an object based on some words and values."
words [any-word! block!] "Word or block of words"
values [any-type!] "Value or block of values"
/any "Allows setting words to any value, including unset"
/local object
][
object: make object! either block? words [length? words] [1]
apply :set [bind/copy/new :words object :values any]
object
]
Both of these create objects with self, so if you want to create an object without self you have to do some fancier tricks. See the selfless proposal for details.

I wrote a similar function (Rebol2) just a few days ago:
build-object: func [
"Builds an object from a block"
names [block!] "Field names"
/values val [block!] "Initial values"
/local o name value
] [
o: copy []
names: compose names
o: either values [
parse names [
some [
set name [word! | set-word!]
(append o to-set-word name)
| skip
]
]
set/pad reflect o: context append o none 'words val
o
] [
if any [
parse names [
some [
set name [word! | set-word!]
(append o reduce [to-set-word name none])
]
]
parse names [
(clear o) some [
set name [word! | set-word!] set value any-type!
(append o reduce [to-set-word name :value])
]
]
] [context o]
]
o
]
To build your object you could write any of: (create a function as f: does ["x"])
build-object [name "Fork" id 1020]
build-object [name: "Fork" id: 1020]
build-object/values [name id] ["Fork" 1020]
build-object/values [name: id:] ["Fork" 1020]
build-object [name f]
build-object [name (f)] ;block is composed
build-object [name 5 id f]
build-object [name 5 id 'f]
You can also make objects with fields set to none if you leave the values out, e.g. with
build-object [name id]

Related

Reconstructing Map in Groovy

May I ask is it possible in groovy to transform the map recursively by removing all the key and only keep the value for maps with certain key prefix (e.g. pk-).
Example from this:
[
applications:[
pk-name-AppA:[name:AppA, keyA1:valueA1Prod, keyA2:valueA2],
pk-name-AppB:[name:AppB, keyB1:valueB1Prod, keyB2:valueB2],
otherAppC:[name:AppC, keyA1:valueA1Prod, keyA2:valueA2]
]
]
to
[
applications:[
[name:AppA, keyA1:valueA1Prod, keyA2:valueA2],
[name:AppB, keyB1:valueB1Prod, keyB2:valueB2],
otherAppC:[name:AppC, keyA1:valueA1Prod, keyA2:valueA2]
]
]

Python Iterating through List of List

Heres my code
stockList = [
['AMD', '57.00', '56.23', '58.40', '56.51'],
['AMZN', '3,138.29', '3,111.03', '3242.56689', '3,126.58'],
['ATVI', '80.76', '79.16', '81.86', '79.55'],
['BA', '178.63', '168.86', '176.96', '169.70'],
['BAC', '24.42', '23.43', '23.95', '23.54'],
['DAL', '26.43', '25.53', '26.87', '25.66'],
['FB', '241.75', '240.00', '248.06', '241.20'],
['GE', '7.04', '6.76', '6.95', '6.79'],
['GOOGL', '1,555.92', '1,536.36', '1,576.03', '1,544.04'],
['GPS', '12.77', '12.04', '12.72', '12.10'],
['GRUB', '70.96', '69.71', '70.65', '70.06'],
['HD', '262.42', '258.72', '261.81', '260.01'],
['LUV', '33.62', '32.45', '33.53', '32.61'],
['MSFT', '208.75', '206.72', '213.58', '207.76'],
['MU', '51.52', '50.49', '52.31', '50.74'],
['NFLX', '490.10', '492.26', '511.52', '494.72', 'SUCCESS'],
['PCG', '9.49', '8.96', '9.52', '9.01'],
['PFE', '36.69', '35.87', '37.02', '36.05'],
['QQQ', '264.00', '263.27', '267.11', '264.58', 'SUCCESS'],
['ROKU', '153.36', '148.37', '153.70', '149.11'],
['SHOP', '952.83', '976.45', '1,036.25', '981.33', 'SUCCESS'],
['SPY', '325.01', '323.64', '325.47', '325.25', 'SUCCESS'],
['SQ', '126.99', '125.13', '130.80', '125.76'],
['T', '30.25', '29.58', '30.07', '29.73'],
['TSLA', '1,568.36', '1,646.56', '1,712.58', '1,654.79', 'SUCCESS'],
['TTWO', '153.06', '152.45', '154.47', '153.22', 'SUCCESS'],
['TWTR', '37.01', '36.03246', '36.7210083', '36.21'],
['WFC', '26.20', '24.45272', '25.0438213', '24.57'],
['WMT', '132.33', '130.8515', '132.522049', '131.51']
]
keyword = 'SUCCESS'
secondList = []
for item in stockList:
if item[4] == keyword:
secondList.append(stockList[0])
print(secondList)
My use case is, to go through this lists of list, find which list contains the keyword, from there send the first item in the list. I am able to get it with one single list, however I can't do it with a list of list.
On top of that, how would I go through a dictionary containing lists?
{
'majorDimension': 'ROWS',
'range': 'Sheet1!A2:F30',
'values': [
['AMD', '57.00', '56.23', '58.40', '56.51'],
['AMZN', '3,138.29', '3,111.03', '3242.56689', '3,126.58'],
['ATVI', '80.76', '79.16', '81.86', '79.55'],
['BA', '178.63', '168.86', '176.96', '169.70'],
['BAC', '24.42', '23.43', '23.95', '23.54'],
['DAL', '26.43', '25.53', '26.87', '25.66'],
['FB', '241.75', '240.00', '248.06', '241.20'],
['GE', '7.04', '6.76', '6.95', '6.79'],
['GOOGL', '1,555.92', '1,536.36', '1,576.03', '1,544.04'],
['GPS', '12.77', '12.04', '12.72', '12.10'],
['GRUB', '70.96', '69.71', '70.65', '70.06'],
['HD', '262.42', '258.72', '261.81', '260.01'],
['LUV', '33.62', '32.45', '33.53', '32.61'],
['MSFT', '208.75', '206.72', '213.58', '207.76'],
['MU', '51.52', '50.49', '52.31', '50.74'],
['NFLX', '490.10', '492.26', '511.52', '494.72', 'SUCCESS'],
['PCG', '9.49', '8.96', '9.52', '9.01'],
['PFE', '36.69', '35.87', '37.02', '36.05'],
['QQQ', '264.00', '263.27', '267.11', '264.58', 'SUCCESS'],
['ROKU', '153.36', '148.37', '153.70', '149.11'],
['SHOP', '952.83', '976.45', '1,036.25', '981.33', 'SUCCESS'],
['SPY', '325.01', '323.64', '325.47', '325.25', 'SUCCESS'],
['SQ', '126.99', '125.13', '130.80', '125.76'],
['T', '30.25', '29.58', '30.07', '29.73'],
['TSLA', '1,568.36', '1,646.56', '1,712.58', '1,654.79', 'SUCCESS'],
['TTWO', '153.06', '152.45', '154.47', '153.22', 'SUCCESS'],
['TWTR', '37.01', '36.03246', '36.7210083', '36.21'],
['WFC', '26.20', '24.45272', '25.0438213', '24.57'],
['WMT', '132.33', '130.8515', '132.522049', '131.51'],
]
}
List comprehension makes this pretty simple. Try the following:
keyword = "SUCCESS"
# PEP8 calls for lower_underscore_case here
second_list = [i[0] for i in stockList if keyword in i]
print(second_list)
For the proposed dictionary structure, you'd just access the key containing the list, since not every value in that dict is a list:
second_list = [i[0] for i in stockList["values"] if keyword in i]
Based upon your question understanding. Your question is divided into two parts, these are:
How to iterate over list of lists, and get the first item from the nested list, and store it in another list
How to iterate over dictionary item, to perform the same operation
If my understanding is right, then you might want to check this out.
Please note: I have not used variable keyword, simply used "SUCCESS", just replace keyword with "SUCCESS" in the code, and you are good to go.
1. FIRST SOLUTION
# to get nested list
for item in stockList:
# this checks whether SUCCESS is present inside a list
# python way of doing it
if "SUCCESS" in item: secondList.append(item[0])
print(secondList)
# OUTPUT
# >>> ['NFLX', 'QQQ', 'SHOP', 'SPY', 'TSLA', 'TTWO']
OR
You can do this in more pythonic way, that is to use List Comprehension
# single line approach, getting the same result
secondList = [item[0] for item in stockList if "SUCCESS" in item]
print(secondList)
# OUTPUT
# >>> ['NFLX', 'QQQ', 'SHOP', 'SPY', 'TSLA', 'TTWO']
2. SECOND SOLUTION
In order to get the result, first you need to assign the Dictionary to your variable, in my case, I have assigned to a variable called stockListDictionary
secondList = []
# to get a value from key specifically
# likt any dictionary key dictionary["key_name"]
for item in stockListDictionary["values"]:
if "SUCCESS" in item: secondList.append(item[0])
print(secondList)
# OUTPUT
# >>> ['NFLX', 'QQQ', 'SHOP', 'SPY', 'TSLA', 'TTWO']
OR
Using List Comprehension
secondList = [item[0] for item in stockListDictionary["values"] if "SUCCESS" in item]
print(secondList)
# OUTPUT
# >>> ['NFLX', 'QQQ', 'SHOP', 'SPY', 'TSLA', 'TTWO']
What about something like this?
keywords={"SUCCESS"}
d = # the dictionary
second_list = list()
for nested_lists in d["values"]:
for stock_info in nested_lists:
stock_ticker = stock_info[0]
if stock_ticker in keywords:
info = set(stock_info[1:])
if info & keywords:
second_list.append(stock_ticker)
Is this better? It should allow you to have more than one keyword.

Not sure how to create ArangoDB graph using columns in existing collection

Background
I have a rocksdb collection that contains three fields: _id, author, subreddit.
Problem
I would like to create a Arango graph that creates a graph connecting these two existing columns. But the examples and the drivers seem to only accept collections as its edge definitions.
Issue
The ArangoDb documentation is lacking information on how I can create a graph using edges and nodes pulled from the same collection.
EDIT:
Solution
This was fixed with a code change at this Arangodb issues ticket.
Here's one way to do it using jq, a JSON-oriented command-line tool.
First, an outline of the steps:
1) Use arangoexport to export your author/subredit collection to a file, say, exported.json;
2) Run the jq script, nodes_and_edges.jq, shown below;
3) Use arangoimp to import the JSON produced in (2) into ArangoDB.
There are several ways the graph can be stored in ArangoDB, so ultimately you might wish to tweak nodes_and_edges.jq accordingly (e.g. to generate the nodes first, and then the edges).
INDEX
If your jq does not have INDEX defined, then use this:
def INDEX(stream; idx_expr):
reduce stream as $row ({};
.[$row|idx_expr|
if type != "string" then tojson
else .
end] |= $row);
def INDEX(idx_expr): INDEX(.[]; idx_expr);
nodes_and_edges.jq
# This module is for generating JSON suitable for importing into ArangoDB.
### Generic Functions
# nodes/2
# $name must be the name of the ArangoDB collection of nodes corresponding to $key.
# The scheme for generating key names can be altered by changing the first
# argument of assign_keys, e.g. to "" if no prefix is wanted.
def nodes($key; $name):
map( {($key): .[$key]} ) | assign_keys($name[0:1] + "_"; 1);
def assign_keys(prefix; start):
. as $in
| reduce range(0;length) as $i ([];
. + [$in[$i] + {"_key": "\(prefix)\(start+$i)"}]);
# nodes_and_edges facilitates the normalization of an implicit graph
# in an ArangoDB "document" collection of objects having $from and $to keys.
# The input should be an array of JSON objects, as produced
# by arangoexport for a single collection.
# If $nodesq is truthy, then the JSON for both the nodes and edges is emitted,
# otherwise only the JSON for the edges is emitted.
#
# The first four arguments should be strings.
#
# $from and $to should be the key names in . to be used for the from-to edges;
# $name1 and $name2 should be the names of the corresponding collections of nodes.
def nodes_and_edges($from; $to; $name1; $name2; $nodesq ):
def dict($s): INDEX(.[$s]) | map_values(._key);
def objects: to_entries[] | {($from): .key, "_key": .value};
(nodes($from; $name1) | dict($from)) as $fdict
| (nodes($to; $name2) | dict($to) ) as $tdict
| (if $nodesq then $fdict, $tdict | objects
else empty end),
(.[] | {_from: "\($name1)/\($fdict[.[$from]])",
_to: "\($name2)/\($tdict[.[$to]])"} ) ;
### Problem-Specific Functions
# If you wish to generate the collections separately,
# then these will come in handy:
def authors: nodes("author"; "authors");
def subredits: nodes("subredit"; "subredits");
def nodes_and_edges:
nodes_and_edges("author"; "subredit"; "authors"; "subredits"; true);
nodes_and_edges
Invocation
jq -cf extract_nodes_edges.jq exported.json
This invocation will produce a set of JSONL (JSON-Lines) for "authors", one for "subredits" and an edge collection.
Example
exported.json
[
{"_id":"test/115159","_key":"115159","_rev":"_V8JSdTS---","author": "A", "subredit": "S1"},
{"_id":"test/145120","_key":"145120","_rev":"_V8ONdZa---","author": "B", "subredit": "S2"},
{"_id":"test/114474","_key":"114474","_rev":"_V8JZJJS---","author": "C", "subredit": "S3"}
]
Output
{"author":"A","_key":"name_1"}
{"author":"B","_key":"name_2"}
{"author":"C","_key":"name_3"}
{"subredit":"S1","_key":"sid_1"}
{"subredit":"S2","_key":"sid_2"}
{"subredit":"S3","_key":"sid_3"}
{"_from":"authors/name_1","_to":"subredits/sid_1"}
{"_from":"authors/name_2","_to":"subredits/sid_2"}
{"_from":"authors/name_3","_to":"subredits/sid_3"}
Please note that the following queries take a while to complete on this huge dataset, however they should complete sucessfully after some hours.
We start the arangoimp to import our base dataset:
arangoimp --create-collection true --collection RawSubReddits --type jsonl ./RC_2017-01
We use arangosh to create the collections where our final data is going to live in:
db._create("authors")
db._createEdgeCollection("authorsToSubreddits")
We fill the authors collection by simply ignoring any subsequently occuring duplicate authors;
We will calculate the _key of the author by using the MD5 function,
so it obeys the restrictions for allowed chars in _key, and we can know it later on by calling MD5() again on the author field:
db._query(`
FOR item IN RawSubReddits
INSERT {
_key: MD5(item.author),
author: item.author
} INTO authors
OPTIONS { ignoreErrors: true }`);
After the we have filled the second vertex collection (we will keep the imported collection as the first vertex collection) we have to calculate the edges.
Since each author can have created several subreds, its most probably going to be several edges originating from each author. As previously mentioned,
we can use the MD5()-function again to reference the author previously created:
db._query(`
FOR onesubred IN RawSubReddits
INSERT {
_from: CONCAT('authors/', MD5(onesubred.author)),
_to: CONCAT('RawSubReddits/', onesubred._key)
} INTO authorsToSubreddits")
After the edge collection is filled (which may again take a while - we're talking about 40 million edges herer, right? - we create the graph description:
db._graphs.save({
"_key": "reddits",
"orphanCollections" : [ ],
"edgeDefinitions" : [
{
"collection": "authorsToSubreddits",
"from": ["authors"],
"to": ["RawSubReddits"]
}
]
})
We now can use the UI to browse the graphs, or use AQL queries to browse the graph. Lets pick the sort of random first author from that list:
db._query(`for author IN authors LIMIT 1 RETURN author`).toArray()
[
{
"_key" : "1cec812d4e44b95e5a11f3cbb15f7980",
"_id" : "authors/1cec812d4e44b95e5a11f3cbb15f7980",
"_rev" : "_W_Eu-----_",
"author" : "punchyourbuns"
}
]
We identified an author, and now run a graph query for him:
db._query(`FOR vertex, edge, path IN 0..1
OUTBOUND 'authors/1cec812d4e44b95e5a11f3cbb15f7980'
GRAPH 'reddits'
RETURN path`).toArray()
One of the resulting paths looks like that:
{
"edges" : [
{
"_key" : "128327199",
"_id" : "authorsToSubreddits/128327199",
"_from" : "authors/1cec812d4e44b95e5a11f3cbb15f7980",
"_to" : "RawSubReddits/38026350",
"_rev" : "_W_LOxgm--F"
}
],
"vertices" : [
{
"_key" : "1cec812d4e44b95e5a11f3cbb15f7980",
"_id" : "authors/1cec812d4e44b95e5a11f3cbb15f7980",
"_rev" : "_W_HAL-y--_",
"author" : "punchyourbuns"
},
{
"_key" : "38026350",
"_id" : "RawSubReddits/38026350",
"_rev" : "_W-JS0na--b",
"distinguished" : null,
"created_utc" : 1484537478,
"id" : "dchfe6e",
"edited" : false,
"parent_id" : "t1_dch51v3",
"body" : "I don't understand tension at all."
"Mine is set to auto."
"I'll replace the needle and rethread. Thanks!",
"stickied" : false,
"gilded" : 0,
"subreddit" : "sewing",
"author" : "punchyourbuns",
"score" : 3,
"link_id" : "t3_5o66d0",
"author_flair_text" : null,
"author_flair_css_class" : null,
"controversiality" : 0,
"retrieved_on" : 1486085797,
"subreddit_id" : "t5_2sczp"
}
]
}
For a graph you need an edge collection for the edges and vertex collections for the nodes. You can't create a graph using only one collection.
Maybe this topic in the documentations is helpful for you.
Here's an AQL solution, which however presupposes that all the referenced collections already exist, and that UPSERT is not necessary.
FOR v IN testcollection
LET a = v.author
LET s = v.subredit
FILTER a
FILTER s
LET fid = (INSERT {author: a} INTO authors RETURN NEW._id)[0]
LET tid = (INSERT {subredit: s} INTO subredits RETURN NEW._id)[0]
INSERT {_from: fid, _to: tid} INTO author_of
RETURN [fid, tid]

RBParser message nodes and targeting the receiver and the argument?

Trying to get some of my old code up and running in Pharo. Some method names are different but after some hardship I managed to find equivalents that work.
I am parsing my code and I'd like to check if the receiver or any of the arguments is aSymbol in an effort to match them to supported alternatives. I've managed to do this to selectors, by analysing RBMessageNode s
aNode selector == aSymbol ifTrue: [ aNode selector: replacementSymbol ].
How can this be done to arguments and receivers? Is there a comprehensive guide on RBParser somewhere?
By direct manipulation
Assuming that you are looking for cases like this:
aSymbol message: aSymbol message: aSymbol
For receiver you should do:
(aNode isMessage and: [
aNode receiver isVariable and: [
aNode receiver name = 'aSymbol' ]]) ifTrue: [
"do your job here" ]
Here is another example on how to replace #aSymbol arguments with #newSymbol:
messageNode arguments: (messageNode arguments collect: [ :arg |
(arg isLiteralNode and: [ arg value = #aSymbol ])
ifFalse: [ arg ]
ifTrue: [ | newNode |
newNode := #aNewSymbol asLiteralNode.
arg replaceSourceWith: newNode.
newNode ] ]).
methodClass compile: ast newSource
The replaceSourceWith: makes sure that just a source will be replaced, but for newSource to actually return a new source you also need to swap the nodes themselves, that's why I'm doing a collect on arguments and return the new ones where needed.
You can view help about RBParser in Word Menu > Help > Help Browser > Refactoring Framework.
You can also play around by inspecting
RBParser parseExpression: 'aSymbol message: aSymbol message: aSymbol'
and looking at its contents
By Parse Tree Transformation
You can use pattern code to match and replace certain code. For example to change the symbol argument of a perform: message you can do this:
ast := yourMethod parseTree.
rewriter := RBParseTreeRewriter new
replace: '`receiver perform: #aSymbol'
with: '`receiver perform: #newSelector'.
(rewriter executeTree: ast) ifTrue: [
yourMethod class compile: ast newSource ]
You can learn more about the pattern matching syntax in the help topic Word Menu > Help > Help Browser > Refactoring Framework > Refactoring Engine > RBPatternParser …. I thing that MatchTool from pharo catalog can greatly help you in testing the match expressions (it also has a dedicated help topic about the matching syntax) while RewriteTool can help you to preview how your code will be transformed.

How do I extract a string value from a cell so I can check its datatype? Intro Matlab Q

Part of my assignment is testing what datatype is stored in my "studentNames" variable.
However I believe that because the studentNames are being held within a cell that MATLAB cant detect the datatype.
How could I solve this problem?
Editor Window
function [studentCell] =classCellArray(studentNames, studentIDs, studentGrades)
studentCell(1,:) = [ **studentNames{1,:}** studentIDs(1,:) studentGrades(1,:) {mean(studentGrades(1,:))}];
studentCell(2,:) = [ studentNames{2,:} studentIDs(2,:) studentGrades(2,:) {mean(studentGrades(2,:))}];
studentCell(3,:) = [ studentNames{3,:} studentIDs(3,:) studentGrades(3,:) {mean(studentGrades(3,:))}];
studentCell(4,:) = [ studentNames{4,:} studentIDs(4,:) studentGrades(4,:) {mean(studentGrades(4,:))}];
Command window
studentCell =
'Ali' 'G10293' [1x3 double] [82.6667]
'Yin' 'G10498' [1x3 double] [ 93]
'Bob' 'G10201' [1x3 double] [56.6667]
'Jim' 'G19532' [1x3 double] [ 100]
EDU>> class(studentNames)
Error using subsindex
Function 'subsindex' is not defined for values of class 'cell'.**

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