Split a String At Uppercase Letters

Split a string at uppercase letters, but only if a lowercase letter follows in Python

We can try using re.sub here for a regex approach:

inp = "2018Annual ReportInvesting for Growth and Market LeadershipOur CEO will provide you with all further details below."
inp = re.sub(r'(?<![A-Z\W])(?=[A-Z])', ' ', inp)
print(inp)

This prints:

2018 Annual Report Investing for Growth and Market Leadership Our CEO will provide you with all further details below.

The regex used here says to insert a space at any point for which:

(?<![A-Z\W])  what precedes is a word character EXCEPT
              for capital letters
(?=[A-Z])     and what follows is a capital letter

Javascript Split string on UpperCase Characters

I would do this with .match() like this:

'ThisIsTheStringToSplit'.match(/[A-Z][a-z]+/g);

it will make an array like this:

['This', 'Is', 'The', 'String', 'To', 'Split']

edit: since the string.split() method also supports regex it can be achieved like this

'ThisIsTheStringToSplit'.split(/(?=[A-Z])/); // positive lookahead to keep the capital letters

that will also solve the problem from the comment:

"thisIsATrickyOne".split(/(?=[A-Z])/);

Java: Split string when an uppercase letter is found

You may use a regexp with zero-width positive lookahead - it finds uppercase letters but doesn't include them into delimiter:

String s = "thisIsMyString";
String[] r = s.split("(?=\\p{Upper})");

Y(?=X) matches Y followed by X, but doesn't include X into match. So (?=\\p{Upper}) matches an empty sequence followed by a uppercase letter, and split uses it as a delimiter.

See javadoc for more info on Java regexp syntax.

EDIT: By the way, it doesn't work with thisIsMyÜberString. For non-ASCII uppercase letters you need a Unicode uppercase character class instead of POSIX one:

String[] r = s.split("(?=\\p{Lu})");

Python - Split a string but keep contiguous uppercase letters

Use re.split with a capturing group (to keep the splitter pattern) and filter out the empty chunks:

import re


def split_by_title_word(s):
    return [chunk for chunk in re.split(r"([A-Z][a-z]+)", s) if chunk]


print(split_by_title_word("splitThreeWords"))
print(split_by_title_word("SplitThreeWords"))
print(split_by_title_word("IOLSummit"))

Output

['split', 'Three', 'Words']
['Split', 'Three', 'Words']
['IOL', 'Summit']

The pattern [A-Z][a-z]+ represents a title word.

How to split a string at uppercase letters from a dataframe column?

You can only call .info() on a pandas.DataFrame, not on a pandas.Series.

Assuming Unicainstancia_DF is a DataFrame, you could call: Unicainstancia_DF.info(), but not Unicainstancia_DF['TesteNomeJuiz'].info()

You're using a series/column selector when you use Unicainstancia_DF['TesteNomeJuiz'] --
you've selected a column (or 'Series') from a DataFrame and are about to do something with it.

What, precisely, you want to do with that Series isn't clear to me from your example. If you want to split on A-Z, then you could do something like this:

import re

print([re.split(r'[A-Z]', x) for x in Unicainstancia_DF['TesteNomeJuiz']]

But as Chris suggests, if you clarify your expected output and where you're wanting to store the splits I can be more specific. It seems doubtful that you actually want to split on A-Z -- more likely is that you want to split on the boundary between A-Z and any other character. Is that the case?

Split a string by Uppercase as long as the each word is not all caps already

Here's my approach:

static IEnumerable<string> SplitCamelCase(string input)
{
   return Regex.Split(input, @"([A-Z]?[a-z]+)").Where(str => !string.IsNullOrEmpty(str));
}

It works by splitting the string using "an uppercase letter followed by one or more lowercase letters" (or just one or more lowercase letters) as a delimiter. string.Split will include the delimiters in the result array if they are captured in parentheses (and they are, in my example). And this leaves only the spans of capital letters (all but the last) occurring between delimiters, which string.Split will include in the array naturally. It does produce superfluous empty strings in some cases, but they can be filtered out; I did so with a .Where clause.

It's not bad. I only wish there were a nicer way to eliminate the empty strings more easily.

By the way, I elected to return IEnumerable<string> because I feel like that format is more reusable. But you can always .ToArray() the result if you prefer an array, or the result can be joined with spaces using string.Join(" ", result) to form your corrected string.

Here's a complete demonstration:

class Program
{
    static IEnumerable<string> SplitCamelCase(string input)
    {
        return Regex.Split(input, @"([A-Z]?[a-z]+)").Where(str => !string.IsNullOrEmpty(str));
    }

    static void Main(string[] args)
    {
        string[] examples = new string[] {
            "FYYear",
            "CostCenter",
            "cosTCenter",
            "CostcenteR",
            "COSTCENTER"
        };
        foreach (string str in examples) {
            Console.WriteLine("{0, 10} -> {1}", str, String.Join(" ", SplitCamelCase(str)));
        }
    }
}

Output:

    FYYear -> FY Year
CostCenter -> Cost Center
cosTCenter -> cos T Center
CostcenteR -> Costcente R
COSTCENTER -> COSTCENTER

Split string on non consecutive capital letters

I believe [A-Z]+[a-z]* meets your requirements:

>>> re.findall(r'[A-Z]+[a-z]*', my_string)
['TTest', 'String', 'AA']

How to split a string at uppercase letters in two scripts

You may create a regex for re using custom character classes for all lower- and uppercase Unicode letters. See Python regex for unicode capitalized words for details how to do that. Here is an example Python code:

import re

pLu = "A-Z\u00C0-\u00D6\u00D8-\u00DE\u0100\u0102\u0104\u0106\u0108\u010A\u010C\u010E\u0110\u0112\u0114\u0116\u0118\u011A\u011C\u011E\u0120\u0122\u0124\u0126\u0128\u012A\u012C\u012E\u0130\u0132\u0134\u0136\u0139\u013B\u013D\u013F\u0141\u0143\u0145\u0147\u014A\u014C\u014E\u0150\u0152\u0154\u0156\u0158\u015A\u015C\u015E\u0160\u0162\u0164\u0166\u0168\u016A\u016C\u016E\u0170\u0172\u0174\u0176\u0178\u0179\u017B\u017D\u0181\u0182\u0184\u0186\u0187\u0189-\u018B\u018E-\u0191\u0193\u0194\u0196-\u0198\u019C\u019D\u019F\u01A0\u01A2\u01A4\u01A6\u01A7\u01A9\u01AC\u01AE\u01AF\u01B1-\u01B3\u01B5\u01B7\u01B8\u01BC\u01C4\u01C7\u01CA\u01CD\u01CF\u01D1\u01D3\u01D5\u01D7\u01D9\u01DB\u01DE\u01E0\u01E2\u01E4\u01E6\u01E8\u01EA\u01EC\u01EE\u01F1\u01F4\u01F6-\u01F8\u01FA\u01FC\u01FE\u0200\u0202\u0204\u0206\u0208\u020A\u020C\u020E\u0210\u0212\u0214\u0216\u0218\u021A\u021C\u021E\u0220\u0222\u0224\u0226\u0228\u022A\u022C\u022E\u0230\u0232\u023A\u023B\u023D\u023E\u0241\u0243-\u0246\u0248\u024A\u024C\u024E\u0370\u0372\u0376\u037F\u0386\u0388-\u038A\u038C\u038E\u038F\u0391-\u03A1\u03A3-\u03AB\u03CF\u03D2-\u03D4\u03D8\u03DA\u03DC\u03DE\u03E0\u03E2\u03E4\u03E6\u03E8\u03EA\u03EC\u03EE\u03F4\u03F7\u03F9\u03FA\u03FD-\u042F\u0460\u0462\u0464\u0466\u0468\u046A\u046C\u046E\u0470\u0472\u0474\u0476\u0478\u047A\u047C\u047E\u0480\u048A\u048C\u048E\u0490\u0492\u0494\u0496\u0498\u049A\u049C\u049E\u04A0\u04A2\u04A4\u04A6\u04A8\u04AA\u04AC\u04AE\u04B0\u04B2\u04B4\u04B6\u04B8\u04BA\u04BC\u04BE\u04C0\u04C1\u04C3\u04C5\u04C7\u04C9\u04CB\u04CD\u04D0\u04D2\u04D4\u04D6\u04D8\u04DA\u04DC\u04DE\u04E0\u04E2\u04E4\u04E6\u04E8\u04EA\u04EC\u04EE\u04F0\u04F2\u04F4\u04F6\u04F8\u04FA\u04FC\u04FE\u0500\u0502\u0504\u0506\u0508\u050A\u050C\u050E\u0510\u0512\u0514\u0516\u0518\u051A\u051C\u051E\u0520\u0522\u0524\u0526\u0528\u052A\u052C\u052E\u0531-\u0556\u10A0-\u10C5\u10C7\u10CD\u13A0-\u13F5\u1E00\u1E02\u1E04\u1E06\u1E08\u1E0A\u1E0C\u1E0E\u1E10\u1E12\u1E14\u1E16\u1E18\u1E1A\u1E1C\u1E1E\u1E20\u1E22\u1E24\u1E26\u1E28\u1E2A\u1E2C\u1E2E\u1E30\u1E32\u1E34\u1E36\u1E38\u1E3A\u1E3C\u1E3E\u1E40\u1E42\u1E44\u1E46\u1E48\u1E4A\u1E4C\u1E4E\u1E50\u1E52\u1E54\u1E56\u1E58\u1E5A\u1E5C\u1E5E\u1E60\u1E62\u1E64\u1E66\u1E68\u1E6A\u1E6C\u1E6E\u1E70\u1E72\u1E74\u1E76\u1E78\u1E7A\u1E7C\u1E7E\u1E80\u1E82\u1E84\u1E86\u1E88\u1E8A\u1E8C\u1E8E\u1E90\u1E92\u1E94\u1E9E\u1EA0\u1EA2\u1EA4\u1EA6\u1EA8\u1EAA\u1EAC\u1EAE\u1EB0\u1EB2\u1EB4\u1EB6\u1EB8\u1EBA\u1EBC\u1EBE\u1EC0\u1EC2\u1EC4\u1EC6\u1EC8\u1ECA\u1ECC\u1ECE\u1ED0\u1ED2\u1ED4\u1ED6\u1ED8\u1EDA\u1EDC\u1EDE\u1EE0\u1EE2\u1EE4\u1EE6\u1EE8\u1EEA\u1EEC\u1EEE\u1EF0\u1EF2\u1EF4\u1EF6\u1EF8\u1EFA\u1EFC\u1EFE\u1F08-\u1F0F\u1F18-\u1F1D\u1F28-\u1F2F\u1F38-\u1F3F\u1F48-\u1F4D\u1F59\u1F5B\u1F5D\u1F5F\u1F68-\u1F6F\u1FB8-\u1FBB\u1FC8-\u1FCB\u1FD8-\u1FDB\u1FE8-\u1FEC\u1FF8-\u1FFB\u2102\u2107\u210B-\u210D\u2110-\u2112\u2115\u2119-\u211D\u2124\u2126\u2128\u212A-\u212D\u2130-\u2133\u213E\u213F\u2145\u2160-\u216F\u2183\u24B6-\u24CF\u2C00-\u2C2E\u2C60\u2C62-\u2C64\u2C67\u2C69\u2C6B\u2C6D-\u2C70\u2C72\u2C75\u2C7E-\u2C80\u2C82\u2C84\u2C86\u2C88\u2C8A\u2C8C\u2C8E\u2C90\u2C92\u2C94\u2C96\u2C98\u2C9A\u2C9C\u2C9E\u2CA0\u2CA2\u2CA4\u2CA6\u2CA8\u2CAA\u2CAC\u2CAE\u2CB0\u2CB2\u2CB4\u2CB6\u2CB8\u2CBA\u2CBC\u2CBE\u2CC0\u2CC2\u2CC4\u2CC6\u2CC8\u2CCA\u2CCC\u2CCE\u2CD0\u2CD2\u2CD4\u2CD6\u2CD8\u2CDA\u2CDC\u2CDE\u2CE0\u2CE2\u2CEB\u2CED\u2CF2\uA640\uA642\uA644\uA646\uA648\uA64A\uA64C\uA64E\uA650\uA652\uA654\uA656\uA658\uA65A\uA65C\uA65E\uA660\uA662\uA664\uA666\uA668\uA66A\uA66C\uA680\uA682\uA684\uA686\uA688\uA68A\uA68C\uA68E\uA690\uA692\uA694\uA696\uA698\uA69A\uA722\uA724\uA726\uA728\uA72A\uA72C\uA72E\uA732\uA734\uA736\uA738\uA73A\uA73C\uA73E\uA740\uA742\uA744\uA746\uA748\uA74A\uA74C\uA74E\uA750\uA752\uA754\uA756\uA758\uA75A\uA75C\uA75E\uA760\uA762\uA764\uA766\uA768\uA76A\uA76C\uA76E\uA779\uA77B\uA77D\uA77E\uA780\uA782\uA784\uA786\uA78B\uA78D\uA790\uA792\uA796\uA798\uA79A\uA79C\uA79E\uA7A0\uA7A2\uA7A4\uA7A6\uA7A8\uA7AA-\uA7AE\uA7B0-\uA7B4\uA7B6\uFF21-\uFF3A\U00010400-\U00010427\U000104B0-\U000104D3\U00010C80-\U00010CB2\U000118A0-\U000118BF\U0001D400-\U0001D419\U0001D434-\U0001D44D\U0001D468-\U0001D481\U0001D49C\U0001D49E\U0001D49F\U0001D4A2\U0001D4A5\U0001D4A6\U0001D4A9-\U0001D4AC\U0001D4AE-\U0001D4B5\U0001D4D0-\U0001D4E9\U0001D504\U0001D505\U0001D507-\U0001D50A\U0001D50D-\U0001D514\U0001D516-\U0001D51C\U0001D538\U0001D539\U0001D53B-\U0001D53E\U0001D540-\U0001D544\U0001D546\U0001D54A-\U0001D550\U0001D56C-\U0001D585\U0001D5A0-\U0001D5B9\U0001D5D4-\U0001D5ED\U0001D608-\U0001D621\U0001D63C-\U0001D655\U0001D670-\U0001D689\U0001D6A8-\U0001D6C0\U0001D6E2-\U0001D6FA\U0001D71C-\U0001D734\U0001D756-\U0001D76E\U0001D790-\U0001D7A8\U0001D7CA\U0001E900-\U0001E921\U0001F130-\U0001F149\U0001F150-\U0001F169\U0001F170-\U0001F189"
rx = r'[{0}][^{0}]*'.format(pLu)
print(re.findall(rx,'TheLongAndWindingRoad')) # =>['The', 'Long', 'And', 'Winding', 'Road']
print(re.findall(rx,'MyNameIsΔημητρης')) # => ['My', 'Name', 'Is', 'Δημητρης']
print(re.findall(rx,'ClimbΌλυμποςΌρος')) # => ['Climb', 'Όλυμπος', 'Όρος']

Or, use the PyPi regex module and a solution like

import regex
text = "MyNameIsΔημητρης"
print( regex.split(r'(?<=\p{Ll})(?=\p{Lu})', text) )
# => ['My', 'Name', 'Is', 'Δημητρης']

See the online Python 3 demo.

The (?<=\p{Ll})(?=\p{Lu}) regex matches a location between any Unicode lowercase (\p{Ll}) and uppercase (\p{Lu}) letter.

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