better way than: myPage += 'more html' , ...

Wed Jun 25 20:30:21 EDT 2003

> From: Gerrit Holl [mailto:gerrit at nl.linux.org]
> 
> Another way, which has not yet been mentioned but which I like much,
> is the cStringIO module. You can write to a string as if it is a
> file:
> 
>   0 >>> import cStringIO
>   1 >>> mystr = cStringIO.StringIO()
>   2 >>> mystr.write("<html")
>   3 >>> mystr.write("<body>")
>   4 >>> mystr.write("<h1>Header</h1>")
>   5 >>> mystr.write("<p>Hello, world!</p>")
>   6 >>> mystr.write("</body></html>")
>  10 >>> mystr.getvalue()
> '<html<body><h1>Header</h1><p>Hello, world!</p></body></html>'
> 
> The cStringIO module is documented at:
> 
> http://www.python.org/dev/doc/devel/lib/module-StringIO.html
> 
> cStringIO is a faster C implementation with the same API.

Indeed, the following might make things nice and easy for you ...

import cStringIO as StringIO

# Subclass of str so that it can be used nearly anywhere that requires a real
# string.

class MutableString (str):

    def __init__ (self, s=""):
        super(MutableString, self).__init__()
        self.data = StringIO.StringIO()
        self.data.write(s)

    def __add__(self, s):
        m = MutableString(self.data.getvalue())
        m.data.write(s)
        return m

    def __iadd__(self, s):
        self.data.write(s)
        return self

    def __str__(self):
        return self.data.getvalue()

    def __repr__(self):
        return repr(str(self))

s = MutableString("Hello,")
s += " world!"
print s
print repr(s)