I have a below string array object which has 4 elements. I want to compare the elements of this list to an string and want to check if string is part of this list.
list = ["starter_v2", "professional_q", "custom_v", "basic_t9"]
str = "starter"
if list.include?str #should return true but returning false as it is checking the full string not the substring
Above if condition should return true, however it is returning false.
Can someone suggest me how to fix this, as I am new to ruby and want to compare strings.
For my usecase, in list object I will always have entries with "_" followed by an alphabetic character and I will compare this by string without "_"
Enumerable#include? checks if a given value matches any value in the given enumerable. A substring is not equivalent to a string that contains it, so this check fails.
Instead, you want to check if any string in the array matches your substring. Ruby has handy facilities for this: Enumerable#any? lets you iterate an enumerable, yielding each element to a block, and then will return true if any invocation of the block returns true.
So, you can use:
list.any? {|element| element.include?(str) }
What this will do is check each entry in list to see if str is included in it; once a match is found, it'll stop iterating and return true. If it goes through the entire list without finding a match, it'll return false.
You could also use use element.start_with? if you know that your search string should always match the first part of the string, or you could use a more complex condition which splits each element on underscore and compares the first part, or you could use a regex. The important part is that the block returns true when you want to indicate a match.
Related
I have string output:
1 4 2 1 4
I want to get each character in string to compare.
I did it to want to know whether the list is sorted yet.
It's not exactly clear to me what you are trying to achieve. Going by "to know whether the list is sorted", and assuming a list of integers, you can use tcl::mathop::< or tcl::mathop::<=, depending on whether you want to allow duplicate values:
if {[tcl::mathop::<= {*}$list]} {
puts "List is sorted"
} else {
puts "List is mixed up"
}
This will also work for ASCII comparison of strings. For more complex comparisons, like using dictionary rules or case insensitive, it's probably easiest to combine that with lsort along with the -indices option:
tcl::mathop::< {*}[lsort -indices -dictionary $list]
The -indices option returns the original index of each list element in sorted order. By checking if those indices are in incremental order, you know if the original list was already sorted.
Of course, if the point of the exercise was to avoid unnecessary sorting, then this is no use. But then again, bubble sort of an already sorted list is very fast and will basically do exactly the comparisons you described. So just sorting will probably be faster than first checking for a sorted list via a scripted loop.
To get each character in the string, do split $the_string "" (yes, on the empty string). That gives you a list of all the characters in the string; you can use foreach to iterate over them. Remember, you can iterate over two (or more) lists at once:
foreach c1 [split $the_string ""] c2 $target_comparison_list {
if {$c1 ne $c2} {
puts "The first not equal character is “$c1” when “$c2” was expected"
break
}
}
Note that it's rarely useful to continue comparison after a difference is found as the most common differences are (relative to the target string) insertions and deletions; almost everything after either of those will differ.
What's the difference between pandas.Series.str.contains and pandas.Series.str.match? Why is the case below?
s1 = pd.Series(['house and parrot'])
s1.str.contains(r"\bparrot\b", case=False)
I got True, but when i do
s1.str.match(r"\bparrot\b", case=False)
I got False. Why is the case?
The documentation for str.contains() states:
Test if pattern or regex is contained within a string of a Series or
Index.
The documentation for str.match() states:
Determine if each string matches a regular expression.
The difference in these two methods is that str.contains() uses: re.search, while str.match() uses re.match.
As per documentation of re.match()
If zero or more characters at the beginning of string match the
regular expression pattern, return a corresponding match object.
Return None if the string does not match the pattern; note that this
is different from a zero-length match.
So parrot does not match the first character of the string so your expression returns False. House does match the first character so it finds house and returns true.
Is there a way to match multiple occurences of string A in string B? Match only return a boolean and Pos only returns the index of the first match it finds.
Maybe split the string into an iterable array based on a common delimiter and return a count somehow?
Well this is one way to solve it. It's not pretty but it works.
=(Length([stringB]) - Length(Replace([stringB];"stringA";""))) / Length("stringA")
The first image below is the parent workflow and the image below that is the child workflow. In the child workflow I check if a singular value I provide is in the list separated by commas I also provide. I use a Regex matcher along with an if node to do this. The problem is the Regex matcher continues to execute for all matches although I want it to stop checking # 2016/05/13 09:08:30, when the expression evaluates to true (the word 'Contract' is present in 'Contract,VMS,Payroll'). I want the Regex matcher to stop and then output isTrue boolean to the variable bar so the parent workflow gets a 'true' instead of the false which it gets now. (which you can see happens in the last activity entry 2016/05/13 09:08:30 where Value is false (since it gets the LAST updated value) for the child workflow).
Hmmm..... There isn't a way to break out of that loop but you should be able to use Regex Match One instead of the loop version as you're actually only interested in determining whether a given pattern matches rather than needing to iterate over each match in order to process it further.
Yes or if its really just s simple string match, use the If Node with expression 'Value like "matchexpression" '
I was getting weird results when doing multiple splits on a string, so I decided to make a simple test to figure out what was going on
testString "1234567891011121314151617181920"
If I wanted to get whats between 10 to 20 in Javascript I would do this:
var results = testString.split("10")[1].split("20")[0]
Which would return 111213141516171819
However when I do this in VB I get 111
Split(testString,"10")(1).Split("20")(0)
It seems the 2nd split is only recognizing the first character no matter what I put.
So it's stopping when it finds the next "2" in the string, even "2abc" would have the same outcome even though that string doesn't even exist.
String.Split does not have an overload that takes only a String. The argument is a Char array or String array. Your string is probably being converted to a char array. Explicitly pass a string array like so:
testString.Split(New String() { "10" }, StringSplitOptions.None)
Try wrapping the second split so it's fashioned like the first one, i.e.:
Split( Split(testString,"10")(1), "20" )(0)"
Vb treats the delimiter argument only as a single character.
This is a tricky scenario that I have seen trip people up before, so I think it is worth a little more explanation than the other answers give. In your original format Split(testString,"10")(1).Split("20")(0), you are unknowingly using two DIFFERENT Split functions.
The first Split(testString,"10") is using the Microsoft.VisualBasic.Strings.Split function, which takes String type parameters. http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.strings.split(v=vs.110).aspx
The second .Split("20")(0) is using System.String.Split method, which does not have an overload that takes a String parameter. http://msdn.microsoft.com/en-us/library/System.String.Split(v=vs.110).aspx
So what was happening is:
Split(testString,"10") uses Microsoft.VisualBasic.Strings.Split, which
returns new String() {"123456789", "11121314151617181920"}
(1) means get 1st position of the returned array, which is "11121314151617181920"
"11121314151617181920".Split("20")(0) uses System.String.Split, and attempts to split on string separator "20"
NOTE: The string "20" param gets implicitly converted to a char "2" because the only single parameter overload of String.Split has a signature of Public Function Split (ParamArray separator As Char()) As String(). The ParamArray parameter option allows you to pass a comma delimited list of values into the function, similar to how String.Format works with a dynamic # of replacement values. http://msdn.microsoft.com/en-us/library/538f81ec.aspx
Step 3 code becomes "11121314151617181920".Split(new Char() {CChar("20")})(0), which using literal values is "11121314151617181920".Split(new Char() {"2"c})(0). The result is {"111", "13141516171819", "0"}. Get the 0th position, returns "111".
So to avoid confusion, you should convert your code to use the same version of Split on both sides.
Either of the 2 examples below should work:
Example 1: Using Microsoft.VisualBasic.Strings.Split:
Split( Split(testString,"10")(1), "20" )(0)
Example 2: Using System.String.Split:
testString _
.Split(New String() {"10"}, StringSplitOptions.None)(1) _
.Split(New String() {"20"}, StringSplitOptions.None)(0)