Passing variable to another function

[JonnyDriller]

Hopefully you guys can see this image. Apoligies about the massive watermark...I need an new cloud I think...
Anyways sorry Michael.
I was very hopeful that this was going to work.
Object oriented programming, sounds good, though perhaps a bit complicated for a big n00been00b like me but I thought well I'll just have to roll with it.
Unfortunately my first experience hasn't been great :(

Now what I did was to rename Database.txt to Database1.txt
Then I copied that file as Database2.txt

When I run the script, as you see, its giving: -

Traceback (most recent call last):
File "/home/pi/Desktop/Pyread.py", line 47, in <module>
dat1 = Data_file("Database1.txt")
NameError: name 'Data_file' is not defined

And I definitely don't have the skills to troubleshoot this. Though I did try to replace Database1.txt with the full path name instead. Same error

I discovered debuggers in my attempt to solve this... when I run the debugger in Thorny, it seems to me that the class exists.
When the debugger gets to that line it shows

Name_________________Value
Data_File _____________<class'__main__.Data_File'>