Re: [Tutor] Convert os.random output to a string
Alan I am planning to store the passwords encrypted. This part is allow a user to generate and view the generated password. Ben got me pointed to a snippet I can use. I was trying to do something the hard way. Jay On 03/06/2014 07:34 PM, Alan Gauld wrote: On 06/03/14 23:32, Jay Lozier wrote: I am try to generate random password strings of an arbitrary user selected length. I read to generate a random string of a user supplied length I can use os.urandom(n). So far so good... > I want to convert the output to a human readable string. Define human readable? I would like to store the string for later processing. Depending on the application there may be laws/rules/guidance prohibiting the storage of passwords. Best practice only ever stores the encrypted form not the original password (or more properly nowadays pass-phrase since phrases are more secure than words.) Also, I would like to limit the characters to the US keyboard, so I might be using the wrong function. Even in the US not everyone uses a "US keyboard" especially nowadays with various tablets/phablets/phones in use. but if you stick to the printable subset of the old ASCII set you should be close enough... But that probably means building your own random generator based on the subrange of characters. I am probably missing something very obvious. Maybe, or you could be asking for more than the library gives? -- Jay Lozier jsloz...@gmail.com ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Convert os.random output to a string
On 06/03/14 23:32, Jay Lozier wrote: I am try to generate random password strings of an arbitrary user selected length. I read to generate a random string of a user supplied length I can use os.urandom(n). So far so good... > I want to convert the output to a human readable string. Define human readable? I would like to store the string for later processing. Depending on the application there may be laws/rules/guidance prohibiting the storage of passwords. Best practice only ever stores the encrypted form not the original password (or more properly nowadays pass-phrase since phrases are more secure than words.) Also, I would like to limit the characters to the US keyboard, so I might be using the wrong function. Even in the US not everyone uses a "US keyboard" especially nowadays with various tablets/phablets/phones in use. but if you stick to the printable subset of the old ASCII set you should be close enough... But that probably means building your own random generator based on the subrange of characters. I am probably missing something very obvious. Maybe, or you could be asking for more than the library gives? -- Alan G Author of the Learn to Program web site http://www.alan-g.me.uk/ http://www.flickr.com/photos/alangauldphotos ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Convert os.random output to a string
Jay Lozier writes: > I am try to generate random password strings of an arbitrary user > selected length. My first recommendation would be: Don't re-invent the wheel. Generating password strings is a complex request, not because it's particularly difficult but because the requirements are complex. Research what other solutions have been published https://duckduckgo.com/?q=generate+password+python> and see whether you still need to write something different. -- \ “Any intelligent fool can make things bigger and more complex… | `\It takes a touch of genius – and a lot of courage – to move in | _o__)the opposite direction.” —Albert Einstein | Ben Finney ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Convert os.random output to a string
Hi, My first question I am try to generate random password strings of an arbitrary user selected length. I read to generate a random string of a user supplied length I can use os.urandom(n). I want to convert the output to a human readable string. I would like to store the string for later processing. Also, I would like to limit the characters to the US keyboard, so I might be using the wrong function. The following is the output from my terminal - Python 3.3.4 on Manjaro Linux shows the generation of a random : Python 3.3.4 (default, Feb 11 2014, 15:56:08) [GCC 4.8.2 20140206 (prerelease)] on linux Type "help", "copyright", "credits" or "license" for more information. >>> from os import urandom >>> a = urandom(16) >>> type(a) >>> a_str = a.decode() Traceback (most recent call last): File "", line 1, in UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb1 in position 0: invalid start byte >>> I am probably missing something very obvious. Thanks in advance! -- Jay Lozier jsloz...@gmail.com ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to determine which function code is being called from
On Thu, Mar 6, 2014 at 12:00 PM, Jignesh Sutar wrote:
> Hi I'm trying to exclude a certain line of code if the function is called by
> another function, see illustration below:
As other have said, this is not often a good idea. That said, it is
possible to inspect the call stack to see what called a particular
function, like this (python 3.3):
iimport inspect
def funcA():
caller = inspect.stack()[1][3]
print('funcA was called by ' + caller)
if caller == '':
print("running from funcA")# print only if running from funcA
if caller in ('', 'funcB'):
print("running from funcA or funcB") # print when running from
either function
if caller == 'funcB':
print("running from funcB") # print only when running from funcB
def funcB():
funcA()
print('- Calling funcA() directly -')
funcA()
print('- Calling funcB() -')
funcB()
Output:
>>>
- Calling funcA() directly -
funcA was called by
running from funcA
running from funcA or funcB
- Calling funcB() -
funcA was called by funcB
running from funcA or funcB
running from funcB
>>>
--
Jerry
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Re: [Tutor] How to determine which function code is being called from
On Thu, Mar 6, 2014 at 9:00 AM, Jignesh Sutar wrote: > Hi I'm trying to exclude a certain line of code if the function is called by > another function, see illustration below: > > > def funcA(): > print "running from funcA" # print only if running from funcA > print "running from funcA or funcB" #print when running from either > function > print "running from funcB" # print only when running from funcB > > def funcB(): > funcA() > > funcB() Can you directly pass the state that funcA cares about as an explicit parameter? I think we need to understand what you're trying to do in context. Tell us more why you want to do what you're doing. Maybe the approach you're taking is correct, or maybe there's an easier way to accomplish what you're trying to do. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to determine which function code is being called from
Jignesh Sutar Wrote in message: > > Hi I'm trying to exclude a certain line of code if the function is called by another function, see illustration below: Your code example is all confused, so perhaps you are as well. Why should any of your code in function A care who calls it? The main point about making functions is to reuse code without caring who is calling it. If the function is going to have variable behavior, control that by passing parameters. Or perhaps this is testing code or debugging code. In that case, look at docs.python.org/2/library/inspect.org and look at function inspect.getouterframes () Can you give a nontrivial use example, and without using recursion? -- DaveA ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to determine which function code is being called from
On 03/06/2014 06:00 PM, Jignesh Sutar wrote: Hi I'm trying to exclude a certain line of code if the function is called by another function, see illustration below: def funcA(): print "running from funcA" # print only if running from funcA print "running from funcA or funcB" #print when running from either function print "running from funcB" # print only when running from funcB def funcB(): funcA() funcB() The simple way is to have a param telling about the caller. (But _probably_ you don't _really_ need that, it is instead an artifact of unproper design.) denis ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] How to determine which function code is being called from
While there are ways of getting at the caller using introspection, there are no reliable ways of doing so and you would do well to rethink the need and take an alternate course such as passing a parameter in. Suppose the following: funcC=funcB what would you want to see? Emile On 3/6/2014 9:00 AM, Jignesh Sutar wrote: Hi I'm trying to exclude a certain line of code if the function is called by another function, see illustration below: def funcA(): print "running from funcA" # print only if running from funcA print "running from funcA or funcB" #print when running from either function print "running from funcB" # print only when running from funcB def funcB(): funcA() funcB() ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] How to determine which function code is being called from
Hi I'm trying to exclude a certain line of code if the function is called by another function, see illustration below: def funcA(): print "running from funcA" # print only if running from funcA print "running from funcA or funcB" #print when running from either function print "running from funcB" # print only when running from funcB def funcB(): funcA() funcB() ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
