list of tuple

[steph bagnis]

Hi !
I'm a new python programmer and I'm searching some tools for working
with tuples's list.
For example I have a list like that :
[('+',4,3),('+',3,9),'('+',5,6),('x',10),('x',3)]
and I would like to get a list with just the tuple with index 0 '+' or
things like that. The question is : is it possible without doing a
loop ?

Thx

 

[Peter Hansen]

I'm a new python programmer and I'm searching some tools for working
with tuples's list.
For example I have a list like that :
[('+',4,3),('+',3,9),'('+',5,6),('x',10),('x',3)]
and I would like to get a list with just the tuple with index 0 '+' or
things like that. The question is : is it possible without doing a
loop ?

I guess it depends on what you consider a loop to be:

For example, a list comprehension should do the trick:

newlist = [x[0] for x in oldlist]

(This is equivalent to a for loop that goes through each item
in the old list, appending the 0-th element of each tuple to a new
list as it goes.)

-Peter

 

[Russell Blau]

I'm a new python programmer and I'm searching some tools for working
with tuples's list.
For example I have a list like that :
[('+',4,3),('+',3,9),'('+',5,6),('x',10),('x',3)]
and I would like to get a list with just the tuple with index 0 '+' or
things like that. The question is : is it possible without doing a
loop ?

I guess it depends on what you consider a loop to be:

For example, a list comprehension should do the trick:

newlist = [x[0] for x in oldlist]

(This is equivalent to a for loop that goes through each item
in the old list, appending the 0-th element of each tuple to a new
list as it goes.)

If I understood the OP correctly, he wants to select those tuples that have
a '+' as the first item. So maybe he wants:

newlist = [x for x in oldlist if x[0] == '+']