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Test a list

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  Test a list Ana Dionísio <anadionisio257@gmail.com> - 2013-03-20 11:15 -0700
    Re: Test a list timothy crosley <timothy.crosley@gmail.com> - 2013-03-20 11:24 -0700
    Re: Test a list Joel Goldstick <joel.goldstick@gmail.com> - 2013-03-20 14:26 -0400
    Re: Test a list Tim Chase <python.list@tim.thechases.com> - 2013-03-20 13:36 -0500
    Re: Test a list Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-03-20 18:40 +0000
    Re: Test a list John Gordon <gordon@panix.com> - 2013-03-20 20:39 +0000

#41610 — Test a list

t= [3,5,6,7,10,14,17,21]

Basically I want to print Test 1 when i is equal to an element of the list "t" and print Test 2 when i is not equal:


while i<=25:

    if i==t[]:

       print "Test1"

    else:

       print "Test2"

What is missing here for this script work?

Thank you all

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#41611

Hi Ana, 

if I understand your question correctly, all you have to do to test this is to write:

if i in t:
   print "Test1"
else:
   print "Test2"

On Wednesday, March 20, 2013 2:15:27 PM UTC-4, Ana Dionísio wrote:
> t= [3,5,6,7,10,14,17,21]
> 
> 
> 
> Basically I want to print Test 1 when i is equal to an element of the list "t" and print Test 2 when i is not equal:
> 
> 
> 
> 
> 
> while i<=25:
> 
> 
> 
>     if i==t[]:
> 
> 
> 
>        print "Test1"
> 
> 
> 
>     else:
> 
> 
> 
>        print "Test2"
> 
> 
> 
> What is missing here for this script work?
> 
> 
> 
> Thank you all

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#41612

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On Wed, Mar 20, 2013 at 2:15 PM, Ana Dionísio <anadionisio257@gmail.com>wrote:

>
> t= [3,5,6,7,10,14,17,21]
>
> Basically I want to print Test 1 when i is equal to an element of the list
> "t" and print Test 2 when i is not equal:
>
>
> while i<=25:
>

You test i, but you don't set i to anything, or change it in your loop

you may want to try

  for i in range(25)  (or perhaps range(1,26)  i'm guessing.  Be more clear

>
>     if i==t[]:
>

This isn't legal syntax.  Try googling about for loops and sets.  Try again
and come back

>
>        print "Test1"
>
>     else:
>
>        print "Test2"
>
> What is missing here for this script work?
>
> Thank you all
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
Joel Goldstick
http://joelgoldstick.com

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#41613

On 2013-03-20 11:15, Ana Dionísio wrote:
> t= [3,5,6,7,10,14,17,21]
> 
> Basically I want to print Test 1 when i is equal to an element of
> the list "t" and print Test 2 when i is not equal:
> 
> while i<=25:
>     if i==t[]:
>        print "Test1"
>     else:
>        print "Test2"
> 
> What is missing here for this script work?

Well, your code never increments "i", so it will loop forever; you
also don't subscript "t" with anything, so you have invalid syntax
there; you also don't have any values in the list that actually match
their 0-indexed offset, so even if your code was correct, it would
still (correctly) return Test2 for everything.

This sounds a bit like homework, but the Pythonic way would likely
iterate over the data and its enumeration:

  for index, value in enumerate(t):
    if index == value: # compare index & value accordingly
     ...

If you need to have the index start at 1 (or some other value)
instead of 0, and you're running Python2.6+, you can pass the initial
index to enumerate().  Otherwise, you have to do the math in your
comparison.

-tkc

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#41614

On Wed, 20 Mar 2013 11:15:27 -0700, Ana Dionísio wrote:

> t= [3,5,6,7,10,14,17,21]
> 
> Basically I want to print Test 1 when i is equal to an element of the
> list "t" and print Test 2 when i is not equal:

Wouldn't it make more sense to print "Equal" and "Not equal"?

If all you want to do is check whether some value i can be found in the 
list, you can do this:

if i in t:
    print "Found"
else:
    print "Not found"



If you want to find the index of where a value is found, use the index 
method:

x = 10
t.index(x)  # returns 4



> while i<=25: 
>     if i==t[]:
>        print "Test1"
>     else:
>        print "Test2"
> 
> What is missing here for this script work?

Lots of things. What's i? Does it ever change, or is it a constant? What 
are you comparing it to?


Taking a wild guess at what you mean, you could try this:


for i in range(25):
    print i, "found" if i in t else "not found"



Does this help?


-- 
Steven

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#41621

In <121be20a-c02a-4b0e-a86f-7c69597b9296@googlegroups.com> =?ISO-8859-1?Q?Ana_Dion=EDsio?= <anadionisio257@gmail.com> writes:


> t= [3,5,6,7,10,14,17,21]

> Basically I want to print Test 1 when i is equal to an element of the
> list "t" and print Test 2 when i is not equal:

> while i<=25:

>     if i==t[]:

>        print "Test1"

>     else:

>        print "Test2"

> What is missing here for this script work?

1. You're missing an initial value for i.
2. You never increment i, so the while loop will never exit.
3. The syntax 'if i==t[]' is wrong.
4. The way you have this code set up, you would need two loops: an outer
   loop for i from 1 to 25, and an inner loop for the items in t.
5. As others have said, this is a poor way to go about it.  You want to
   use "if i in t".

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon@panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"

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