True, they are built to handle exceptions. but they can be overused. Unless you know that you might get an exception and you might need to catch something to handle it, there's no point to using them. More often, they are used to mask errors rather than actually do something good (like catch exceptions). :)
On 12/2/2010 1:34 PM, qubit wrote:
Hi Ty --I disagree about the try block -- try blocks are defined to assist in error recovery. The sample code Ken sent maybe skips the exceptions, but you could change that by adding handlers for the various exceptions.Just musing. --le ----- Original Message ----- *From:* Littlefield, Tyler <mailto:tyler@xxxxxxxxxxxxx> *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Sent:* Thursday, December 02, 2010 1:48 PM *Subject:* Re: Python: Making A Program Run A Function That Is Not Hard Coded On another note, I wouldn't surround your function call in a try block like Ken did. That's bad practice and will just mask the errors. If you get errors, they should generally be dealt with, not hidden. If you do anything in that function that throws an error, it'll just be skipped because the call to it was wrapped in a try block. On 12/2/2010 12:35 PM, Homme, James wrote:Hi Ty, Can you please explain what you said? Thanks. Jim Jim Homme, Usability Services, Phone: 412-544-1810. Skype: jim.homme Internal recipients, Read my accessibility blog <http://mysites.highmark.com/personal/lidikki/Blog/default.aspx>. Discuss accessibility here <http://collaborate.highmark.com/COP/technical/accessibility/default.aspx>. Accessibility Wiki: Breaking news and accessibility advice <http://collaborate.highmark.com/COP/technical/accessibility/Accessibility%20Wiki/Forms/AllPages.aspx> *From:*programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Littlefield, Tyler *Sent:* Thursday, December 02, 2010 2:27 PM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* Re: Python: Making A Program Run A Function That Is Not Hard Coded Use Ken's code, not what Jim gave you. Jim's code will add a key and a return value to the dict where as Ken's will allow you to call the code with dict['func]() On 12/2/2010 12:13 PM, Ken Perry wrote: That is not my code below. ken *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Homme, James *Sent:* Thursday, December 02, 2010 1:59 PM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded Hi Ken, Maybe I'm still not getting it. When I use the code below, the function doesn't print anything out. # A dictionary of functions that could possibly run. # Note that we have parentheses in the values because it litterally runs them as code. myfuncs = { "func1" : "func1()", "func2" : "func2()" } # Two functions with parameters that we don't use. def func1(x = "x"): """Func1: Print something to prove this runs""" print "func 1" def func2(x = "x"): """Func2: Print something to prove this runs""" print "func 2" # Run the code contained in the first element of the above dictionary. myfuncs["func1"] raw_input("Press enter to quit") Jim Jim Homme, Usability Services, Phone: 412-544-1810. Skype: jim.homme Internal recipients, Read my accessibility blog <http://mysites.highmark.com/personal/lidikki/Blog/default.aspx>. Discuss accessibility here <http://collaborate.highmark.com/COP/technical/accessibility/default.aspx>. Accessibility Wiki: Breaking news and accessibility advice <http://collaborate.highmark.com/COP/technical/accessibility/Accessibility%20Wiki/Forms/AllPages.aspx> *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Ken Perry *Sent:* Thursday, December 02, 2010 1:10 PM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded Actually I don't know why you guys are dead set on using eveal this is how I do it and it gives you the ability to add parameters later without changing the code. In fact I have used this in all kinds of ways to help sort functions for weird reasons. Here is how I do a dictionary of functions. def func1(): print "func 1" def func2(): print "func 2" myFuncs={"s1":func1,"s2":func2} myFuncs["s2"]() *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Homme, James *Sent:* Thursday, December 02, 2010 10:56 AM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded Hi, Here is code that uses a dictionary rather than a list. Note that I will later add the exception code. But this works. # A dictionary of functions that could possibly run. # Note that we have parentheses in the values because it litterally runs them as code. myfuncs = { "func1" : "func1()", "func2" : "func2()" } # Two functions with parameters that we don't use. def func1(x = "x"): """Func1: Print something to prove this runs""" print "func 1" def func2(x = "x"): """Func2: Print something to prove this runs""" print "func 2" # Run the code contained in the first element of the above dictionary. eval(myfuncs["func1"]) raw_input("Press enter to quit") Jim Jim Homme, Usability Services, Phone: 412-544-1810. Skype: jim.homme Internal recipients, Read my accessibility blog <http://mysites.highmark.com/personal/lidikki/Blog/default.aspx>. Discuss accessibility here <http://collaborate.highmark.com/COP/technical/accessibility/default.aspx>. Accessibility Wiki: Breaking news and accessibility advice <http://collaborate.highmark.com/COP/technical/accessibility/Accessibility%20Wiki/Forms/AllPages.aspx> *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Ken Perry *Sent:* Thursday, December 02, 2010 10:15 AM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded You don't need the quotes around the func in the dictionary. *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Homme, James *Sent:* Thursday, December 02, 2010 8:56 AM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded Hi, When I try to execute this code, nothing prints to the screen. How do I debug it? myfuncs = { "string1" : "func1", "string2" : "func2" } def func1(): print "func 1" def func2(): print "func 2" eval(myfuncs["string1"]) raw_input("Press enter to quit") Thanks. Jim Jim Homme, Usability Services, Phone: 412-544-1810. Skype: jim.homme Internal recipients, Read my accessibility blog <http://mysites.highmark.com/personal/lidikki/Blog/default.aspx>. Discuss accessibility here <http://collaborate.highmark.com/COP/technical/accessibility/default.aspx>. Accessibility Wiki: Breaking news and accessibility advice <http://collaborate.highmark.com/COP/technical/accessibility/Accessibility%20Wiki/Forms/AllPages.aspx> *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Ken Perry *Sent:* Thursday, December 02, 2010 8:06 AM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* RE: Python: Making A Program Run A Function That Is Not Hard Coded When I went looking for the best way to do this it turns out that a dictionary works as a perfect case statement and does all your checking at the same time. Note if you don't use has_key you will need to put it in a try block like this: MyFuncs={"string1",func1,"string2",func2} Def func1(blah): Do something Def func2(bla): Do something Try: Myfuncs["string1"]("pass in") Except: Don't do nothing Note I added a parameter just to show it can be done. Make sure to make the parameters match if you have parameters all functions must have them or at least defaults. Ken *From:* programmingblind-bounce@xxxxxxxxxxxxx <mailto:programmingblind-bounce@xxxxxxxxxxxxx> [mailto:programmingblind-bounce@xxxxxxxxxxxxx] *On Behalf Of *Homme, James *Sent:* Thursday, December 02, 2010 7:55 AM *To:* programmingblind@xxxxxxxxxxxxx <mailto:programmingblind@xxxxxxxxxxxxx> *Subject:* Python: Making A Program Run A Function That Is Not Hard Coded Hi, I'm trying to be clear about this question, but maybe this can't be done. Let's say that you have a list that contains twenty strings. Your program reads in a string from a file. The string from the file matches one of the strings in your list. You want to perform a function that may be associated with that string. You don't want to write twenty if statements to see if the string in the file matches and perform the function associated with that string. You want to somehow get the program to see the string and the function associated with it and just perform it. Is this possible? Thanks. Jim Jim Homme, Usability Services, Phone: 412-544-1810. Skype: jim.homme Internal recipients, Read my accessibility blog <http://mysites.highmark.com/personal/lidikki/Blog/default.aspx>. Discuss accessibility here <http://collaborate.highmark.com/COP/technical/accessibility/default.aspx>. Accessibility Wiki: Breaking news and accessibility advice <http://collaborate.highmark.com/COP/technical/accessibility/Accessibility%20Wiki/Forms/AllPages.aspx> This e-mail and any attachments to it are confidential and are intended solely for use of the individual or entity to whom they are addressed. If you have received this e-mail in error, please notify the sender immediately and then delete it. If you are not the intended recipient, you must not keep, use, disclose, copy or distribute this e-mail without the author's prior permission. The views expressed in this e-mail message do not necessarily represent the views of Highmark Inc., its subsidiaries, or affiliates. --Thanks,Ty--Thanks, Ty
-- Thanks, Ty
