Python One is a library that can convert python programs to C# (more languages coming soon). An import note is that python one does NOT run programs like this:

Run Statement 1
Run Statement 2
Run Statement 3

But like this:

Add statement 1 to ouput
Add statement 2 to ouput
Add statement 3 to ouput
Run output

Another important is that because of this, you can't use normal python, but instead you have to use pythonOne's functions.

Here's an example program:

from pythonOne import *

program = Program("py")
program.set_current_program()

with start():
    printit(str_("Hello World!"))

program.build()

Let's break this down.
First we import pythonOne:

from pythonOne import *

Then we create a program and set it as the current program:

program = Program("py")
program.set_current_program()

If you want to create a program for C#, you would do this:

program = Program("cs")
program.set_current_program()

For the main body of the program we use the start context manager:

with start():

Then we print "Hello World!"

printit(str_("Hello World!"))

The str_ function tells pythonOne that the value is a string.
If you don't use it, and write your code like this:

printit("Hello World!")

you will get an error when you run the output:

  File "output.py", line 5
    print(Hello World!)
                    ^
SyntaxError: invalid syntax

Finally, we build the program, which writes its output to output.py (output.txt for languages other than Python):

program.build()

We can now run this:

% python example.py

And then run the output:

% python output.py