concatenate two txt files

I’m beginner in python, I have two space delimited text files,
the first looks like:

a b c
d e f 

the second looks like:

1 2 3
4 5 6

I want to concatenate them vertically such that the output is:

a b c 
d e f
1 2 3
4 5 6

how can I do that using python?
and if I want to concatenate horizontally so it looks like this:

a b c 1 2 3
d e f 4 5 6

how can I do it also?

>Solution :

Maybe something like that, using join():

with open("File1", 'r') as f:
    file1 = f.read().split("\n")
with open("File2", 'r') as f:
    file2 = f.read().split("\n")

vertically = "\n".join(file1 + file2)
print(vertically)

horizontally = "\n".join([" ".join(line) for line in zip(file1, file2)])
print(horizontally)

To save:

with open("File3.txt", 'w') as f:
    f.write(vertically)

with open("File4.txt", 'w') as f:
    f.write(horizontally)