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# QStringList Class Reference
[QtCore module]

The QStringList class provides a list of strings. More...

### Methods

- __init__ (self)
- __init__ (self, QString i)
- __init__ (self, QStringList l)
- append (self, QString str)
- clear (self)
- bool contains (self, QString str, Qt.CaseSensitivity cs = Qt.CaseSensitive)
- int count (self, QString str)
- int count (self)
- QStringList filter (self, QString str, Qt.CaseSensitivity cs = Qt.CaseSensitive)
- QStringList filter (self, QRegExp rx)
- QString first (self)
- int indexOf (self, QString str, int from = 0)
- int indexOf (self, QRegExp rx, int from = 0)
- insert (self, int i, QString str)
- bool isEmpty (self)
- QString join (self, QString sep)
- QString last (self)
- int lastIndexOf (self, QString str, int from = -1)
- int lastIndexOf (self, QRegExp rx, int from = -1)
- QStringList mid (self, int pos, int length = -1)
- move (self, int from, int to)
- prepend (self, QString str)
- int removeAll (self, QString str)
- removeAt (self, int i)
- int removeDuplicates (self)
- replace (self, int i, QString str)
- QStringList replaceInStrings (self, QString before, QString after, Qt.CaseSensitivity cs = Qt.CaseSensitive)
- QStringList replaceInStrings (self, QRegExp rx, QString after)
- sort (self)
- swap (self, int i, int j)
- QString takeAt (self, int i)
- QString takeFirst (self)
- QString takeLast (self)

### Special Methods

- QStringList __add__ (self, QStringList other)
- int __contains__ (self, QString str)
- __delitem__ (self, int i)
- __delitem__ (self, slice slice)
- bool __eq__ (self, QStringList other)
- QString __getitem__ (self, int i)
- QStringList __getitem__ (self, slice slice)
- QStringList __iadd__ (self, QStringList other)
- QStringList __iadd__ (self, QString value)
- QStringList __imul__ (self, int by)
- int __len__ (self)
- QStringList __lshift__ (self, QString str)
- QStringList __lshift__ (self, QStringList l)
- QStringList __mul__ (self, int by)
- bool __ne__ (self, QStringList other)
- __setitem__ (self, int i, QString str)
- __setitem__ (self, slice slice, QStringList list)

## Detailed Description

A Python list of Python string or unicode objects or QString instances may be used whenever a QStringList is expected.

The QStringList class provides a list of strings.

QStringList inherits from QList<QString>. Like QList, QStringList is implicitly shared. It provides fast index-based access as well as fast insertions and removals. Passing string lists as value parameters is both fast and safe.

All of QList's functionality also applies to QStringList. For example, you can use isEmpty() to test whether the list is empty, and you can call functions like append(), prepend(), insert(), replace(), removeAll(), removeAt(), removeFirst(), removeLast(), and removeOne() to modify a QStringList. In addition, QStringList provides a few convenience functions that make handling lists of strings easier:

- Adding strings
- Iterating over the strings
- Manipulating the strings

### Adding strings

Strings can be added to a list using the append(), operator+=() and operator<<() functions. For example:

         QStringList fonts;
         fonts << "Arial" << "Helvetica" << "Times" << "Courier";

### Iterating over the strings

To iterate over a list, you can either use index positions or QList's Java-style and STL-style iterator types:

Indexing:

         for (int i = 0; i < fonts.size(); ++i)
              cout << fonts.at(i).toLocal8Bit().constData() << endl;

Java-style iterator:

         QStringListIterator javaStyleIterator(fonts);
         while (javaStyleIterator.hasNext())
              cout << javaStyleIterator.next().toLocal8Bit().constData() << endl;

STL-style iterator:

         QStringList.const_iterator constIterator;
         for (constIterator = fonts.constBegin(); constIterator != fonts.constEnd();
                ++constIterator)
             cout << (*constIterator).toLocal8Bit().constData() << endl;

The QStringListIterator class is simply a type definition for QListIterator<QString>. QStringList also provide the QMutableStringListIterator class which is a type definition for QMutableListIterator<QString>.

### Manipulating the strings

QStringList provides several functions allowing you to manipulate the contents of a list. You can concatenate all the strings in a string list into a single string (with an optional separator) using the join() function. For example:

         QString str = fonts.join(",");
          // str == "Arial,Helvetica,Times,Courier"

To break up a string into a string list, use the QString.split() function:

         QStringList list;
         list = str.split(",");
          // list: ["Arial", "Helvetica", "Times", "Courier"]

The argument to split can be a single character, a string, or a QRegExp.

In addition, the operator+() function allows you to concatenate two string lists into one. To sort a string list, use the sort() function.

QString list also provides the filter() function which lets you to extract a new list which contains only those strings which contain a particular substring (or match a particular regular expression):

         QStringList monospacedFonts = fonts.filter(QRegExp("Courier|Fixed"));

The contains() function tells you whether the list contains a given string, while the indexOf() function returns the index of the first occurrence of the given string. The lastIndexOf() function on the other hand, returns the index of the last occurrence of the string.

Finally, the replaceInStrings() function calls QString.replace() on each string in the string list in turn. For example:

         QStringList files;
         files << "$QTDIR/src/moc/moc.y"
               << "$QTDIR/src/moc/moc.l"
               << "$QTDIR/include/qconfig.h";

         files.replaceInStrings("$QTDIR", "/usr/lib/qt");
         // files: [ "/usr/lib/qt/src/moc/moc.y", ...]

See also QString.

## Method Documentation

### QStringList.__init__ (self)

Constructs an empty string list.

### QStringList.__init__ (self, QString i)

Constructs a string list that contains the given string, str. Longer lists are easily created like this:

         QStringList longerList = (QStringList() << str1 << str2 << str3);

See also append().

### QStringList.__init__ (self, QStringList l)

Constructs a copy of the other string list.

This operation takes constant time because QStringList is implicitly shared, making the process of returning a QStringList from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes linear time.

See also operator=().

### QStringList.append (self, QString str)

### QStringList.clear (self)

### bool QStringList.contains (self, QString str, Qt.CaseSensitivity cs = Qt.CaseSensitive)

Returns true if the list contains the string str; otherwise returns false. The search is case insensitive if cs is Qt.CaseInsensitive; the search is case sensitive by default.

See also indexOf(), lastIndexOf(), and QString.contains().

### int QStringList.count (self, QString str)

### int QStringList.count (self)

### QStringList QStringList.filter (self, QString str, Qt.CaseSensitivity cs = Qt.CaseSensitive)

Returns a list of all the strings containing the substring str.

If cs is Qt.CaseSensitive (the default), the string comparison is case sensitive; otherwise the comparison is case insensitive.

         QStringList list;
         list << "Bill Murray" << "John Doe" << "Bill Clinton";

         QStringList result;
         result = list.filter("Bill");
         // result: ["Bill Murray", "Bill Clinton"]

This is equivalent to

         QStringList result;
         foreach (QString str, list) {
             if (str.contains("Bill"))
                 result += str;
         }

See also contains().

### QStringList QStringList.filter (self, QRegExp rx)

This is an overloaded function.

Returns a list of all the strings that match the regular expression rx.

### QString QStringList.first (self)

### int QStringList.indexOf (self, QString str, int from = 0)

Returns the index position of the first exact match of rx in the list, searching forward from index position from. Returns -1 if no item matched.

By default, this function is case sensitive.

See also lastIndexOf(), contains(), and QRegExp.exactMatch().

### int QStringList.indexOf (self, QRegExp rx, int from = 0)

Returns the index position of the first occurrence of value in the list, searching forward from index position from. Returns -1 if no item matched.

See also lastIndexOf(), contains(), and QList.indexOf().

### QStringList.insert (self, int i, QString str)

### bool QStringList.isEmpty (self)

### QString QStringList.join (self, QString sep)

Joins all the string list's strings into a single string with each element separated by the given separator (which can be an empty string).

See also QString.split().

### QString QStringList.last (self)

### int QStringList.lastIndexOf (self, QString str, int from = -1)

Returns the index position of the last exact match of rx in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

See also indexOf(), contains(), and QRegExp.exactMatch().

### int QStringList.lastIndexOf (self, QRegExp rx, int from = -1)

Returns the index position of the last occurrence of value in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

See also indexOf() and QList.lastIndexOf().

### QStringList QStringList.mid (self, int pos, int length = -1)

### QStringList.move (self, int from, int to)

### QStringList.prepend (self, QString str)

### int QStringList.removeAll (self, QString str)

### QStringList.removeAt (self, int i)

### int QStringList.removeDuplicates (self)

This function removes duplicate entries from a list. The entries do not have to be sorted. They will retain their original order.

Returns the number of removed entries.

This function was introduced in Qt 4.5.

### QStringList.replace (self, int i, QString str)

### QStringList QStringList.replaceInStrings (self, QString before, QString after, Qt.CaseSensitivity cs = Qt.CaseSensitive)

Returns a string list where every string has had the before text replaced with the after text wherever the before text is found. The before text is matched case-sensitively or not depending on the cs flag.

For example:

         QStringList list;
         list << "alpha" << "beta" << "gamma" << "epsilon";
         list.replaceInStrings("a", "o");
         // list == ["olpho", "beto", "gommo", "epsilon"]

See also QString.replace().

### QStringList QStringList.replaceInStrings (self, QRegExp rx, QString after)

This is an overloaded function.

Replaces every occurrence of the regexp rx, in each of the string lists's strings, with after. Returns a reference to the string list.

For example:

         QStringList list;
         list << "alpha" << "beta" << "gamma" << "epsilon";
         list.replaceInStrings(QRegExp("^a"), "o");
         // list == ["olpha", "beta", "gamma", "epsilon"]

For regular expressions that contain capturing parentheses, occurrences of \1, \2, ..., in after are replaced with rx.cap(1), rx.cap(2), ...

For example:

         QStringList list;
         list << "Bill Clinton" << "Murray, Bill";
         list.replaceInStrings(QRegExp("^(.*), (.*)$"), "\\2 \\1");
         // list == ["Bill Clinton", "Bill Murray"]

### QStringList.sort (self)

Sorts the list of strings in ascending order (case sensitively).

Sorting is performed using Qt's qSort() algorithm, which operates in linear-logarithmic time, i.e. O(n log n).

If you want to sort your strings in an arbitrary order, consider using the QMap class. For example, you could use a QMap<QString, QString> to create a case-insensitive ordering (e.g. with the keys being lower-case versions of the strings, and the values being the strings), or a QMap<int, QString> to sort the strings by some integer index.

See also qSort().

### QStringList.swap (self, int i, int j)

### QString QStringList.takeAt (self, int i)

### QString QStringList.takeFirst (self)

### QString QStringList.takeLast (self)

### QStringList QStringList.__add__ (self, QStringList other)

### int QStringList.__contains__ (self, QString str)

### QStringList.__delitem__ (self, int i)

### QStringList.__delitem__ (self, slice slice)

### bool QStringList.__eq__ (self, QStringList other)

### QString QStringList.__getitem__ (self, int i)

### QStringList QStringList.__getitem__ (self, slice slice)

### QStringList QStringList.__iadd__ (self, QStringList other)

### QStringList QStringList.__iadd__ (self, QString value)

### QStringList QStringList.__imul__ (self, int by)

### int QStringList.__len__ (self)

### QStringList QStringList.__lshift__ (self, QString str)

### QStringList QStringList.__lshift__ (self, QStringList l)

### QStringList QStringList.__mul__ (self, int by)

### bool QStringList.__ne__ (self, QStringList other)

### QStringList.__setitem__ (self, int i, QString str)

### QStringList.__setitem__ (self, slice slice, QStringList list)