delete lines

[antar2]

I am new in python and I have the following problem:

Suppose I have a list with words of which I want to remove each time
the words in the lines below item1 and above item2:

item1
a
b
item2
c
d
item3
e
f
item4
g
h
item1
i
j
item2
k
l
item3
m
n
item4
o
p

I did not find out how to do this:

Part of my script was

f = re.compile("ite m\[1\]\:")
g = re.compile("ite m\[2\]\:")
for i, line in enumerate(list1 ):
f_match = f.search(line)
g_match = g.search(line)
if f_match:
if g_match:
if list1[i] f_match:
if list1[i] < g_match:
del list1[i]


But this does not work

If someone can help me, thanks!

[Peter Otten]

Re: delete lines

antar2 wrote:

I am new in python and I have the following problem:
>
Suppose I have a list with words of which I want to remove each time
the words in the lines below item1 and above item2:

f = re.compile("ite m\[1\]\:")
g = re.compile("ite m\[2\]\:")
for i, line in enumerate(list1 ):
                f_match = f.search(line)
                g_match = g.search(line)
                if f_match:
                        if g_match:
                                if list1[i] f_match:
                                        if list1[i] < g_match:
                                                del list1[i]
>
>
But this does not work
>
If someone can help me, thanks!

I see two problems with your code:

- You are altering the list while you iterate over it. Don't do that, it'll
cause Python to skip items, and the result is usually a mess. Make a new
list instead.

- You don't keep track of whether you are between "item1" and "item2". A
simple flag will help here.

A working example:

inlist = """item1
a
b
item2
c
d
item3
e
f
item4
g
h
item1
i
j
item2
k
l
item3
m
n
item4
o
p
""".splitlines( )

print inlist

outlist = []
between = False

for item in inlist:
if between:
if item == "item2":
between = False
outlist.append( item)
else:
outlist.append( item)
if item == "item1":
between = True

print outlist

Peter