Separating out a list with regex? - regex

Question

I have a CSV file which has been generated by a system. The problem is with one of the fields which used to be a list of items. An example of the original list is below....
The serial number of the desk is 45TYTU
This is the second item in the list
The colour of the apple is green
The ID code is 489RUI
This is the fourth item in the list.
And unfortunately the system spits out the code below.....
The serial number of the desk is 45TYTUThis is the second item in the listThe colour of the apple is greenThe ID code is 489RUIThis is the fourth item in the list.
As you can see, it ignores the line breaks and just bunches everything up. I am unable to modify the system that generates this output so what I am trying to do is come up with some sort of regex find and replace expression that will separate them out.
My original though would be to try and detect when an upper case letter is in the middle of a lower case word, but as in one of the items in the example, when a serial number is used it throws this out.
Anyone any suggestions? Is regex the way to go?
--- EDIT ---
I think i need to simplify things for myself, if I ignore the fact that lines that end in a serial number will break things for now. I need to just create an expression that will insert a line break if it detects that an upper case letter is being used after a lower case one
--- EDIT 2 ---
Using the example given by fardjad everything works for the sample data given, the strong was...
(.(?=[A-Z][a-z]))
Now as I test with more data I can see an issue appearing, certain lines begin with numbers so it is seeing these as serial numbers, you can see an example of this at http://regexr.com?2vfi5
There are only about 10 known numbers it uses at the start of the lines such as 240v, 120v etc...
Is there a way to exclude these?

Answer 1

That won't be a robust solution but this is what you asked. It matches the character before an uppercase letter followed by a lowercase one. You can simply use regex replace and append a new line character:
(.(?=[A-Z][a-z]))
see this demo.

Answer 2

You could search for this
(?<=\p{Ll})(?=\p{Lu})
and replace with a linebreak. The regex matches the empty space between a lowercase letter \p{Ll} and an uppercase letter \p{Lu}.
This assumes you're using a Unicode-aware regex engine (.NET, PCRE, Perl for example). If not, you might also get away with
(?<=[a-z])(?=[A-Z])
but this of course only detects lower-/uppercase changes in ASCII words.