this seems to read file o.k. but doesn't write to a file HELP

[eric dexter]

This seems to write everything to the shell but not out to a disk file

 
def get_instr(from_file, to_file, instr_num):
    instr_num_str = str(instr_num)
    out_list = []
    infile = open(from_file, 'r')
    for line in infile: # Internally, for calls the files next() method
        line_list = line.split()
        if len(line_list) > 1 and line_list[1] == instr_num_str:
            out_list.append(line)
            while True:
                cmd = infile.next(), # so by the time we get here, we're ready
                cmd_str = cmd[0]
                print repr(cmd_str)
                out_list.append(cmd_str)
                if cmd_str.rstrip() == "endin":
                    break
            break
    infile.close()
    print out_list
    outfile = open(to_file, "w")
    outfile.writelines(out_list)
    outfile.close()
 
 

The test program that call this is simple

 
csoundroutines.get_instr('bay-at-night.csd', 'test.orc', 1)
 
 

this is the traceback if it means anything

Traceback (most recent call last):
File "C:\Python24\Lib\site-packages\boa-constructor\test of snake\test_of_csoundroutines.py", line 4, in ?
csoundroutines.get_instr('bay-at-night.csd', 'test.orc', 1)
File "C:\Python24\Lib\site-packages\boa-constructor\test of snake\csoundroutines.py", line 18, in get_instr
cmd = infile.next(), # so by the time we get here, we're ready
StopIteration

[bartonc]

When I gave you these line of code, it was as a simple example of was to use the itterative nature of file objects. It needs work to prevent it from breaking when search items are not found. A really cool feature of Python is the

try:
do stuff
except(error you want to catch)
break

I the case of your test, it look like you're not finding the "endin".

The book "learning python" from O'reilly has a hole section on what is a good idea to "wrap" in a try block and what is "over-wrapping". I could not have become the programmer that I am without resources like this, even though python documentation is GREAT and can teach you a lot.

[eric dexter]

The errors are a little cryptic at times thanks for the help. I am a little dissapointed in the book I bought and now I am bottem fishing for other titles on ebay (my budget being what it is right now). hopefully it becomes as easy as it looks it should be.

[bartonc]

OK, here's a hint

        try:
            while True:
                cmd = infile.next(), # so by the time we get here, we're ready
                cmd_str = cmd[0]
                out_list.append(cmd_str)
                if cmd_str.rstrip() == "endin":
                    break
        except StopIteration:
            print "Did not find 'endin'"