Python newbie question re Strings and integers

[rmac]

the following code attempts to extract a symbol name from a string:
extensionStart = int(filename.rf ind('.'))
filenameStart = int(filename.rf ind('/'))
#print 'Extension Start - ' + str(extensionSt art)
#print 'FileName Start - ' + str(filenameSta rt)
currentSymbol=f ilename[int(filenameSta rt),int(extensi onStart)]

Uncommenting the print statements clearly show the values to be
integers (and without the str casts actually provide int+string
errors)

However, executing this code results in...
opening - /Users/rmac/Documents/Sandbox/data/MarketData/AA.csv
Traceback (most recent call last):
File "rHistFileToDB_ Equities.py", line 25, in <module>
currentSymbol=f ilename[int(filenameSta rt),int(extensi onStart)]
TypeError: string indices must be integers

Running Python 2.5.2_5 on OSX

[Miki]

Re: Python newbie question re Strings and integers

    currentSymbol=f ilename[int(filenameSta rt),int(extensi onStart)]
Should be
currentSymbol=f ilename[int(filenameSta rt):int(extensi onStart)]
(change , to :)

You don't need to convert to int all the time, rfind will return an
integer.

Also you can use os.path for this

from os.path import basename, splitext
currentSymbol = splitext(basena me(filename))[0]

HTH,
--
Miki <miki.tebeka@gm ail.com>

http://pythonwise.blogspot.com

[Christian Heimes]

Re: Python newbie question re Strings and integers

rmac wrote:

>
the following code attempts to extract a symbol name from a string:
extensionStart = int(filename.rf ind('.'))
filenameStart = int(filename.rf ind('/'))
#print 'Extension Start - ' + str(extensionSt art)
#print 'FileName Start - ' + str(filenameSta rt)
currentSymbol=f ilename[int(filenameSta rt),int(extensi onStart)]
>
Uncommenting the print statements clearly show the values to be
integers (and without the str casts actually provide int+string
errors)
>
However, executing this code results in...
opening - /Users/rmac/Documents/Sandbox/data/MarketData/AA.csv
Traceback (most recent call last):
File "rHistFileToDB_ Equities.py", line 25, in <module>
currentSymbol=f ilename[int(filenameSta rt),int(extensi onStart)]
TypeError: string indices must be integers

You are using , inside filename[]. The splicing syntax is start:end, not
start,end.

You are better off with using the appropriate APIs from the os.path module.

http://docs.python.org/lib/module-os.path.html

import os.path
filename = os.path.basenam e(path)
prefix, extension = os.path.splitex t(filename)

Christian

[rmac]

Re: Python newbie question re Strings and integers


Ah! Arghh!!! You are so correct on the usage of the ':'

Python syntax is a little different from what I am used to.

Thank you.

[Bruno Desthuilliers]

Re: Python newbie question re Strings and integers

rmac a écrit :

Ah! Arghh!!! You are so correct on the usage of the ':'
>
Python syntax is a little different from what I am used to.

I don't know what you're used to, but chances are that more than the
syntax differs !-)