substitution

问题 I was wondering if there is a simple way to do every combination of selected character substitutions in ruby in a simple way. An example: string = "this is a test" subs = ['a'=>'@','i'=>'!','s'=>'$'] subs.combination.each { |c| string.gsub c } would yield "this is @ test" "th!s !s a test" "thi$ i$ a te$t" "th!s !s @ test" "thi$ i$ @ te$t" "th!$ !$ a te$t" "th!$ !$ @ te$t" Thanks for the help! 回答1: string = "this is a test" subs = ['a'=>'@','i'=>'!','s'=>'$'] subs = subs.first.map(&:to_a) 1

问题 This question already has answers here : I just assigned a variable, but echo $variable shows something else (7 answers) Closed 2 years ago . For string matching purposes I need to define a bash variable with leading spaces. I need to define this starting from an integer, like: jj=5 printf seems to me a good idea, so if I want to fill spaces up to 6 character: jpat=`printf " %6i" $jj` but unluckly when I am trying to recall the variable: echo $jpat the leading whitespaces are removed and I

问题 What I would like to do is to make specific substitions in a given text. For example, '<' should be changed to '[', '>' to ']', and so forth. It is similar to the solution given here: How can I do multiple substitutions using regex in python?, which is import re def multiple_replace(dict, text): # Create a regular expression from the dictionary keys regex = re.compile("(%s)" % "|".join(map(re.escape, dict.keys()))) # For each match, look-up corresponding value in dictionary return regex.sub

问题 I have a vector of integers from range [0,3], for example: v = [0,0,1,2,1,3, 0,3,0,2,1,1,0,2,0,3,2,1] . I know that I can replace a specific values of elements in the vector by other value using the following v[v == 0] = 5 which changes all appearences of 0 in vector v to value 5 . But I would like to do something a little bit different - I want to change all values of 0 (let's call them target values ) to 1 , and all values different from 0 to 0 , thus I want to obtain the following: v = [1

问题 Say I have the following two matrices: >> x = [1 4 3; 6 4 3; 6 9 3; 2 4 3; 5 4 0; 5 3 1; 6 4 7]; >> y = [0 0 1; 1 1 0; 1 1 0; 0 1 1; 0.2 0.8 0.54; 1 1 1; 0 0 0]; Where you can think of x as some image, and y the degree of membership of of each element of x to some region of interest. Say I set those elements in x that have degree of membership = 1 to 1 and the other elements to 0 as follows: x = zeros(size(y)); x(y==1) = 1; In which case I will have the following output: 0 0 1 1 1 0 1 1 0 0 1

问题 Let's say I have two variables: a="AAA" b="BBB" I read a string from a file. This string is the following: str='$a $b' How to create a new string from the first one that substitutes the variables? newstr="AAA BBB" 回答1: bash variable indirection whithout eval : Well, as eval is evil , we may try to make this whithout them, by using indirection in variable names. a="AAA" b="BBB" str='$a $b' newstr=() for cnt in $str ;do [ "${cnt:0:1}" == '$' ] && cnt=${cnt:1} && cnt=${!cnt} newstr+=($cnt) done

问题 Which one of these is cheaper? $_ = 'abc123def'; s/\d+/$&*2/e; say; s/(\d+)/$1*2/e; say; 回答1: Executive summary : use 5.010's /p instead. The performance of $& is about the same for a single match or substitution, but the entire program can suffer from it. It's slowdown is long-range, not local. Here's a benchmark with 5.010, which I suspect you are using since you have say in there. Note that 5.010 has a new /p flag that supplies a ${^MATCH} variable that acts like $& but for only one

问题 I am trying to use a PL/SQL script in SQL*Plus to set the linesize and pagesize based on a developer input on whether a report should print in landscape or portrait orientation. If it is landscape, I want linesize 132 and pagesize 60. If it is portrait, I want 88 and 80 respectively. I am trying to use substitution variables to do so like this: DEFINE PRINT_ORIENTATION 'PORTRAIT' COLUMN LINESIZE_VALUE NOPRINT new_value LINE COLUMN PAGESIZE_VALUE NOPRINT new_value PAGE SELECT DECODE('&PRINT

问题 I have a list in Lua which is fixed format (it's an input from somewhere else). E.g. a = {"apple", "apple 1", "pear", "orange", "orange 3", "kiwi", "tomato"} I also have a look up table where I want to normalise this set and send them to a code format. Note: anything containing apple, such as apple 1, apple 2 etc will be mapped to the same value as apple. E.g. "apple" => "RD" "pear" => "GR" "orange" => "OG" "kiwi" => "GR" "tomato" => "RD" "banana" => "YL" etc... I then want to return a list

问题 I am reading each line of an input file (IN) and printing the line read to an output file (OUT) if the line begins with one of the patterns, say "ab", "cd","ef","gh","ij" etc. The line printed is of form "pattern: 100" or form "pattern: 100:200". I need to replace "pattern" with "myPattern", i.e. print the current line to FILE but replace all the text before the first occurence of ":" with "myPattern". What is the best way to do this? Currently I have: while ( <IN> ) { print FILE if /^ab:|^bc