Two string literals next to each other are automatically concatenated;
the first line above could also have been written \samp{word = 'Help'
-'A'}; this only works with two literals, not with arbitrary string expressions.
+'A'}; this only works with two literals, not with arbitrary string
+expressions:
+
+\begin{verbatim}
+>>> 'str' 'ing' # <- This is ok
+'string'
+>>> string.strip('str') + 'ing' # <- This is ok
+'string'
+>>> string.strip('str') 'ing' # <- This is invalid
+ File "<stdin>", line 1
+ string.strip('str') 'ing'
+ ^
+SyntaxError: invalid syntax
+\end{verbatim}
Strings can be subscripted (indexed); like in \C{}, the first character
of a string has subscript (index) 0. There is no separate character
statement. For example:
\begin{verbatim}
+>>> # [Code which sets 'x' to a value...]
>>> if x < 0:
... x = 0
... print 'Negative changed to zero'