[Tutor] making a string

[Tim Hanson]

On Saturday, May 25, 2013 08:31:49 pm Martin A. Brown wrote:
> Greetings Tim,
> 
>  : I'm new to this, just getting through the first Mark Lutz book.
> 
> Python objects, either variables your ham below or the string 'spam'
> you entered manually have a specific type.  Each and every variable
> or object has a type.
> 
> I think you are trying to figure out how you started with a string
> that looked like 'spam' (and Python calls a <type 'str'>) and end up
> with something that looks like:
> 
>    ['s','p','a','m']
> 
> Well, I would encourage you to play with everything at the Python
> prompt.  You should be able to enter a tête-à-tête with Python as
> follows.  This is what I see when I type 'python' and get an
> interactive console:
> 
>   Python 2.7.2 (default, Aug 19 2011, 20:41:43) [GCC] on linux2
>   Type "help", "copyright", "credits" or "license" for more information.
> 
> 
> Then, I can start playing with variables, strings, lists and all the
> other things that Mark Lutz may mention.
> 
> Here's what I actually typed and what Python told me:
>   >>> spam = 'spam'
>   >>> type(spam)
> 
>   <type 'str'>
> 
>   >>> ham = list(spam)
>   >>> type(ham)
> 
>   <type 'list'>
> 
>   >>> viking = ''.join(ham)
>   >>> viking
> 
>   'spam'
> 
>   >>> type(viking)
> 
>   <type 'str'>
> 
> So, the point I'm trying to make here is that you did quite a bit
> 
> in just one line, by calling:
>   >>> ham=list('spam');ham
> 
> Consider playing a bit with the interpreter.
> 
>  : ham=list('spam');ham
>  : ['s','p','a','m']
>  : 
>  : How do I get a string back?
> 
> I will now try to annotate my session above, so that you can maybe
> see how I was able to get a string.
> 
>   >>> spam = 'spam'          # -- variable spam now contains string 'spam'
>   >>> type(spam)
> 
>   <type 'str'>               # -- and Python tells me it's a string
> 
>   >>> ham = list(spam)       # -- I'm running your command
>   >>> type(ham)
> 
>   <type 'list'>              # -- Wait, what!?  It's a list?!  Oh.  Yeah.
> 
>   >>> viking = ''.join(ham)  # -- create a string of the list elements
>   >>> viking
> 
>   'spam'
> 
>   >>> type(viking)           # -- ah, here's our string!
> 
>   <type 'str'>
> 
> Try out the .join(ham) trick with other strings.  For
> 
> example...what happens when you try these yourself:
>   >>> ham = list('spam')
>   >>> '-'.join(ham)
>   >>> ':'.join(ham)
>   >>> 'B'.join(ham)
>   >>> '    '.join(ham)
> 
> Hopefully, you see that there's no magic here at all--just that
> you have learned how create a string with all of the elements in a
> list.  Try something else for your amusement, as well...
> 
>   >>> ' '.join(list('frobnitz'))
> 
> Does that make sense?  Welcome to Python, and Mark Lutz has been
> writing books on Python for almost as long as Python has been
> around.  So, good luck and ask questions here.  There's quite a
> group here willing to help.
> 
> -Martin
The answer was to include ''.join(ham), as in making it a string method 
instead of a function, which doesn't exist.  Thanks!

For me, picking up Python is a retirement project, so no shortage of time to 
learn.

A lot of people tend to be intimidated by Mark Lutz, and so am I, I guess.  
There are a lot of books out there that will get one up and running more 
quickly, but I get the feeling his is _complete_ instruction, not something 
just slopped through.  "Learning Python" has taken a long time.  I'm not sure 
how I'll be able to get through "Programming..."  You'll probably see me on 
the Core list next year sometime.