I am actually trying to validate a string which is mixed case. Example:
WeLComE: this is my default string -- string1.
I am retrieving same string from some other method which is coming as welcome (lower case) -- string2.
When I am comparing both of them and keeping an if test for both the strings to match. But as these both are in different case, I am unable to go inside the if block. So I am doing
if string2 == string1.lower():
which is working for me.
But is there any other way which can ignore the case for the strings and compare them.
Any other method?
Your example is fine. If you are sure that string2 is always in lower case, you can certainly compare with
if string2 == string1.lower():
Or else go with
if string2.lower() == string1.lower():
If you absolutely need a different approach, go with
import re
if re.match("^welcome$", "WeLcOmE", re.I)
Related
This is the part of the code I have copied to see the output,
def check(string,sub_str):
if(string.find(sub_str)==-1):
print('no')
else:
print('yes)
# driver code for testing the above function
string='geeks for geeks'
sub_str='geeks'
I specifically wanted to understand how this expression works :
if(string.find(sub_str)==-1): . Also this code is for finding substrings in a given strings can some one tell if this is the optimal way, I know it is tutorial code but I have an easier way to find the substrings. Just wanted to know if that would make passing test cases easier hence the above code. Anyways thanks y'all for your answers.
The method find() returns the index of the string you are looking for. The string in front of find() is the one in which you are looking for the second string.
SentenceThatIsCompletelySearched.find(ForThisPartHere)
If the string you are looking for is present it will return the index (a number on which position of the sentence the string has been found).
If the string is not inside the sentence then find() will return -1 (a number).
So in your case you are checking if sub_str is inside string and if it is not present (return of -1) you will print "no". If it is you will print "yes".
In TI-BASIC, the + operation is overloaded for string concatenation (in this, if nothing else, TI-BASIC joins the rest of the world).
However, any attempt to concatenate involving an empty string raises a Dimension Mismatch error:
"Fizz"+"Buzz"
FizzBuzz
"Fizz"+""
Error
""+"Buzz"
Error
""+""
Error
Why does this occur, and is there an elegant workaround? I've been using a starting space and truncating the string when necessary (doesn't always work well) or using a loop to add characters one at a time (slow).
The best way depends on what you are doing.
If you have a string (in this case, Str1) that you need to concatenate with another (Str2), and you don't know if it is empty, then this is a good general-case solution:
Str2
If length(Str1
Str1+Str2
If you need to loop and add a stuff to the string each time, then this is your best solution:
Before the loop:
" →Str1
In the loop:
Str1+<stuff_that_isn't_an_empty_string>→Str1
After the loop:
sub(Str1,2,length(Str1)-1→Str1
There are other situations, too, and if you have a specific situation, then you should post a simplified version of the relevant code.
Hope this helps!
It is very unfortunate that TI-Basic doesn't support empty strings. If you are starting with an empty string and adding chars, you have to do something like this:
"?
For(I,1,3
Prompt Str1
Ans+Str1
End
sub(Ans,2,length(Ans)-1
Another useful trick is that if you have a string that you are eventually going to evaluate using expr(, you can do "("+Str1+")"→Str1 and then freely do search and replace on the string. This is a necessary workaround since you can't search and replace any text involving the first or last character in a string.
Hey guys so I tried looking at previous questions but they dont answer it like my teacher wants it to be answered. Basically i need to get a string from a user input and see if it has:
at least one of [!,#,#,$,%,^,&,*,(,)] (non-letter and nonnumeric
character)
o Create a list for these special characters
I have no idea how to make a def to do this. Please help!
You should probably look into Regular expressions. Regular expressions allow you to do many string operations in a concise way. Specifically, you'll want to use re.findall() in order to find all special characters in your string and return them. You can check if the returned list has length 0 to check if there were any special characters at all.
With regards to building the regular expression to find special characters itself... I'm sure you can figure that part out ;)
Please try the below
import re
inputstring = raw_input("Enter String: ")
print inputstring
print "Valid" if re.match("^[a-zA-Z0-9_]*$", inputstring) else "Invalid"
I need to search for a substring in a string and return that if it is there in the string.
What is the best way to do that in Erlang? Note that i dont know the place that substring happens in the bigger string so i need to do a search for that.
You can use a regular expression:
> re:run("foobarbaz", "bar", [{capture, first, list}]).
{match,["bar"]}
See the documentation for re:run/3 for more information. In particular you may find that a different capture option suits your need.
Or if you don't need all the features of regular expressions, string:str/2 might be enough:
> string:str(" Hello Hello World World ", "Hello World").
8
This small function may help you. It returns true if the small string can be found in the big string, otherwise it returns false.
string_contains(Big, Small)->
string:str(Big, Small) > 0.
I have an EditText object (et_travel) on my screen that's asking for miles traveled. I grab that data like this:
float travel = Float.parseFloat(et_travel.getText().toString());
if(travel > 40000){
I just discover that if someone puts 40000 in the EditText, everything works fine, but if they put 40,000 (adding a comma to the number), I force close on the float travel = ...statement.
How can I evaluate the number without having a problem from the user adding a comma?
Is this in Java? It appears to be, but I'm wondering if I'm mistaken. Regardless, I would suggest you remove all of the characters from the string that are not of a numeric type. A way to do this may be using a regular expression.
A way to do this in Java may be the following:
String input = et_travel.getText().toString();
input = input.replaceAll("[^0-9]", "");
float travel = Float.parseFloat(input);
...
This way, you strip anything that is a non-numeric value from the string first, and then attempt to do your work. Obviously do some error checking before this (like input is not null and such). One change that is needed however is that you may need to maintain the '.' character (if you're given non-integer values). This would require changing the first regex a bit.
Check here: http://download.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#replaceAll(java.lang.String, java.lang.String)
What you need is some validation on the input. Before converting the string into a float parse the string. If there are any ','s then remove them. If there is just junk then reject the input, otherwise someone could put a word or anything else in the input and cause havoc in your program.
Check out
inputType to restrict user input
android:inputType="number"