How to return an "not string' error in function?

[breakfastea]

first of all I have to claim that I'm a noob so please help me don't
blame me

for example:

def test(s):
if type(s) != ? :
return
#So here I want establish a situation about that if <s> is not string
#then <return>, but how should write the <?> ?
#Or is there any other way to do it?

Any suggestion would be appreciate

Peace

 

[Tim Chase]

def test(s):

if type(s) != ? :
return
#So here I want establish a situation about that if <s> is not string
#then <return>, but how should write the <?> ?
#Or is there any other way to do it?

True

This will return true for both regular strings and for unicode
strings. If that's a problem, you can use
True

....or, if you don't want to qualify them with "types." each time,
you can use

to bring them into the local namespace.

HTH,

-tkc

 

[breakfastea]

Thank you so much it answers my humble question perfectly

 

[Duncan Booth]

This will return true for both regular strings and for unicode
strings. If that's a problem, you can use

True

...or, if you don't want to qualify them with "types." each time,
you can use


to bring them into the local namespace.

They already are in the builtin namespace under their more usual names of
str and unicode respectively, so there is no need to import them, just use
them:
True

.... etc ...

 

[Cameron Laird]

Thank you so much it answers my humble question perfectly

HOWEVER, to answer you final question, yes, there is a different
and, in general, better, way. While there's a lot to say about
good Python style and typing, I'll summarize at a high level:
you shouldn't have to check types. I can understand that you
are working to make a particular function particularly robust,
and are trying to account for a wide range of inputs. This is
healthy. In stylish Python, though, you generally don't need
type checking. How would it be, for example, if someone passed
the number 3 to your function. Is that an error? Do you want
it automatically interpreted as the string "3"? You can achieve
these results withOUT a sequence of

if isinstance(...
elif isinstance(...
...

perhaps with something as simple as

my_input = str(my_input).

One of us will probably follow-up with a reference to a more
detailed write-up of the subject.

 

[breakfastea]

Or yes that seems a handy way

Thanks for all wonderful people here

Peace

 

[breakfastea]

Thank you for your inputing which has been great inspirational

What I tried to do is to write a string.split() module, so I started
with:

def spilt(a):
l=[]
index=0
if not isinstance(a, basestring): #Or isinstance(a, str)
return
for i in len(a):
if a=' ':
item=a[index:i]
l.append(item)
..................

I'm still working on it

Thank you again

Peace

PS: Is str() the same as repr() ?

 

[Bruno Desthuilliers]

Thank you for your inputing which has been great inspirational

What I tried to do is to write a string.split() module,

So don't waste time:

"ab eced f aazaz".split() ['ab', 'eced', 'f', 'aazaz']
"ab-eced-ff-aazaz".split('-') ['ab', 'eced', 'ff', 'aazaz']

 

[breakfastea]

Thank you for your reminder

However I saw the split() function in the first place and that why I'm
trying write one myself

Peace

Thank you for your inputing which has been great inspirational

What I tried to do is to write a string.split() module,

So don't waste time:

"ab eced f aazaz".split() ['ab', 'eced', 'f', 'aazaz']
"ab-eced-ff-aazaz".split('-') ['ab', 'eced', 'ff', 'aazaz']

 

[Bruno Desthuilliers]

What I tried to do is to write a string.split() module,

So don't waste time:

"ab eced f aazaz".split() ['ab', 'eced', 'f', 'aazaz']
"ab-eced-ff-aazaz".split('-')

['ab', 'eced', 'ff', 'aazaz']

Thank you for your reminder

However I saw the split() function in the first place and that why I'm
trying write one myself

Ok. Then if it's for learning, let's have a look

def spilt(a):

def split(astring, sep=' '):

l=[]
index=0
if not isinstance(a, basestring): #Or isinstance(a, str)
return

It's an error, so you don't want to pass it silently:

if not isinstance(astring, basetring):
raise TypeError('expected a string or unicode, got : %s' \
% type(astring)

for i in len(a):

The common idiom is : "for item in sequence:". If you need indexes too,
use enumerate: "for i, char in enumerate(astring):".

But anyway, you may want to have a look at str.find() or str.index().

if a=' ':
item=a[index:i]
l.append(item)

Good luck...

 

[Cameron Laird]

.
.
.

PS: Is str() the same as repr() ?

.
.
.
No <URL: http://www.thescripts.com/forum/thread19556.html > or
<URL: http://groups.google.com/group/comp.lang.python/browse_thread/thread/f4556ec0bbbeb45c/ >.

 

[Camellia]

I've learned a lot from you two, thank you

Peace