concat

问题 I have a function that produces lazy-sequences called a-function. If I run the code: (map a-function a-sequence-of-values) it returns a lazy sequence as expected. But when I run the code: (mapcat a-function a-sequence-of-values) it breaks the lazyness of my function. In fact it turns that code into (apply concat (map a-function a-sequence-of-values)) So it needs to realize all the values from the map before concatenating those values. What I need is a function that concatenates the result of

问题 I have a function that produces lazy-sequences called a-function. If I run the code: (map a-function a-sequence-of-values) it returns a lazy sequence as expected. But when I run the code: (mapcat a-function a-sequence-of-values) it breaks the lazyness of my function. In fact it turns that code into (apply concat (map a-function a-sequence-of-values)) So it needs to realize all the values from the map before concatenating those values. What I need is a function that concatenates the result of

问题 I have two files: one with x coordinates, and other with y. Is there a way to plot this two files in one graph using gnuplot? Or is there a way to concat row by row this two files? Thanks 回答1: There is not a way to plot the x coordinate from one file and the y coordinate from another natively in gnuplot. If you use a bash-like shell, you can use the command paste x_data.dat y_data.dat > xy_data.dat to combine files row-by row. If you want to put this command into a gnuplot script, you can do

问题 I am trying to column-bind dataframes and having issue with pandas concat , as ignore_index=True doesn't seem to work: df1 = pd.DataFrame({'A': ['A0', 'A1', 'A2', 'A3'], 'B': ['B0', 'B1', 'B2', 'B3'], 'D': ['D0', 'D1', 'D2', 'D3']}, index=[0, 2, 3,4]) df2 = pd.DataFrame({'A1': ['A4', 'A5', 'A6', 'A7'], 'C': ['C4', 'C5', 'C6', 'C7'], 'D2': ['D4', 'D5', 'D6', 'D7']}, index=[ 5, 6, 7,3]) df1 # A B D # 0 A0 B0 D0 # 2 A1 B1 D1 # 3 A2 B2 D2 # 4 A3 B3 D3 df2 # A1 C D2 # 5 A4 C4 D4 # 6 A5 C5 D5 # 7

问题 Hi I have the following dataframes: > df1 id begin conditional confidence discoveryTechnique 0 278 56 false 0.0 1 1 421 18 false 0.0 1 > df2 concept 0 A 1 B How do I merge on the indices to get: id begin conditional confidence discoveryTechnique concept 0 278 56 false 0.0 1 A 1 421 18 false 0.0 1 B I ask because it is my understanding that merge() i.e. df1.merge(df2) uses columns to do the matching. In fact, doing this I get: Traceback (most recent call last): File "<stdin>", line 1, in

问题 How should I concatenate base64 strings in order to get rid of the "=" characters ? I sent a byte stream[] of data from the servlet as a http response, and at the client side I want to open the pdf viewer. But, I can't view it because of these extra characters. I tried to concatenate with +=, with join, with concat, but I still have the = character at the end of each substring. Maybe if there's a way to concat the strings without the last character. 回答1: The standard base-64 encoding encodes

问题 I tried to get select top n data from a database based on alphabetical & numbering format. The output must order by alphabet first and number after that. When I try to get all data ( select * ), I get the correct output: select nocust, share from TB_STOCK where share = ’BBCA’ and concat(share, nocust) < ‘ZZZZZZZZ’ order by case when nocust like ‘[a-z]%’ then 0 else 1 end nocust | share -------+-------- a522 | BBCA b454 | BBCA k007 | BBCA p430 | BBCA q797 | BBCA s441 | BBCA s892 | BBCA u648 |

问题 I have the code: var gulp = require('gulp'); var webpack = require('webpack-stream'); var coffee = require('gulp-coffee'); var concat = require('gulp-concat'); gulp.task('webpack', function() { gulp.src('*/lib/*.coffee', { base: '.' }) .pipe(coffee({ bare: true })) .pipe(concat('app.js')) .pipe(webpack()) .pipe(gulp.dest('.')); }); However, it doesn't work, when it reaches webpack() . How can I make it so that the content passed from concat() to webpack() works successfully? I also assume

问题 By concatenation I mean obtaining a new list, which listens for changes in all concatenated parts. What is the purpose of method FXCollections#concat(ObservableList<E>... lists)? If it just merges several lists, then I see no sense to have separate method for this. And if regard as doing what I wish then it doesn't work: import javafx.collections.FXCollections; import javafx.collections.ListChangeListener; import javafx.collections.ObservableList; public class ConcatObservabeList { public

问题 I have the following code which works fine when run as a Query but returns error message when run as view. I have attached the error message. I think I am missing a brace somewhere. If anyone can help it is much appreciated. SELECT CASE WHEN a.Sex = 1 THEN 'M' WHEN a.Sex = 2 THEN 'F' END AS Derived_Sex, CASE WHEN concat(b.Complete, a.[CALCULATED_AGE]) LIKE 'A%' THEN 'Less than 1' WHEN concat(b.Complete, a.[CALCULATED_AGE]) LIKE 'B%' THEN 'Less than 1' WHEN concat(b.Complete, a.[CALCULATED_AGE