looping through two list simultenously

[CSUIDL PROGRAMMEr]

folks
I have two lists

 i am trying to loop thorough them simultenously.

Here is the code i am using

f1 = os.popen('ls  chatlog*.out')
data1=f1.readlines()
f1.close()

data1=[x.strip() for x in data1]
f1 = os.popen('ls  chatlog*.txt')
data=f1.readlines()
f1.close()
for eachline in data1 and line in data:

    filename='/root/Desktop/project/'+ eachline
    print filename
    outfile=open(filename,'r')
    filename1='/root/Desktop/project/' + line
    print filename1

I get the error that line is not defined.
Traceback (most recent call last):
  File "list.py", line 16, in ?
    for eachline in data1 and line in data:
NameError: name 'line' is not defined

Is there any efficient doing this