Merge 2 lines with delimiter

[Buddhism]

>>> text = '''xxx.xxx.xx.xx
... yyyy
...
...
...
...
...
... xxx.xxx.xx.xx
... yyyy
...
...
...
...
...
... xxx.xxx.xx.xx
... yyyy'''
>>> lines = text.split('\n')
>>> lines
['xxx.xxx.xx.xx', 'yyyy', '', '', '', '', '', 'xxx.xxx.xx.xx', 'yyyy', '', '', '', '', '', 'xxx.xxx.xx.xx', 'yyyy']
>>> lines = [line for line in lines if line] # remove blanks
>>> lines
['xxx.xxx.xx.xx', 'yyyy', 'xxx.xxx.xx.xx', 'yyyy', 'xxx.xxx.xx.xx', 'yyyy']
>>> pairs = [(lines[i-1], lines[i]) for i in range(1, len(lines), 2)]
>>> pairs
[('xxx.xxx.xx.xx', 'yyyy'), ('xxx.xxx.xx.xx', 'yyyy'), ('xxx.xxx.xx.xx', 'yyyy')]
>>> '\n'.join(':'.join(pair) for pair in pairs)
'xxx.xxx.xx.xx:yyyy\nxxx.xxx.xx.xx:yyyy\nxxx.xxx.xx.xx:yyyy'
>>> print('\n'.join(':'.join(pair) for pair in pairs))
xxx.xxx.xx.xx:yyyy
xxx.xxx.xx.xx:yyyy
xxx.xxx.xx.xx:yyyy

This looks very good, but I is from a text file which includes the text.
otherwise I could just do

x = "xxx.xxx.xx.xx"
y = "yyyy"
print (x + ":" + y)
print ("\n")

Or am I wrong?