Accessing variables from a file

Hi,
I have 2 files file1 & file2.
I am trying to open file1 and print str1 and n in file2.
Code:

file1:
str1 = "192.168.10.1"
...
n =var.split('.')[3]
print n

file2:

with open(r"txt.py","r") as f:
for line in f:
if re.search("str1", line):
o1 = str1
print o1
if re.search("n", line):
o2 = n
print o2
f.close()

This throws an error:
global name 'str1' is not defined

Can someone please help me with this?
Thanks