Basic Scripting 101

[catwhowalksbyhimself]

Alright, that nice scripting tutorial is down, which had what I'm looking for now.

Basically, how do you set up a loop that looks in a list and does the same commands on every variable in that list.  For example, have a group of minions, and set the same AI priorities in all of them?

I could do the same thing the long way, but I'd rather learn the better way.

EDIT:  Nevermind.  I looked it up on a general Python tutorial and I think I get how for loops work in Python.  I'll let you know if I get it wrong and need more help.

[stumpy]

There are also some decent examples in the mission.py files for the FFvT3R campaign. Search for the for statements in the mission scripts in 03a_red, 03b_inside, etc.

[catwhowalksbyhimself]

Ah, I was looking, but wasn't sure where to look.

Still, it's similar enough to other programing languages that I think I'll have no real problems.

[catwhowalksbyhimself]

Having problems with lists, or libraries, or whatever in the world they're called.  I can't find a thing that I could have done wrong, so someone be a dear and help me out.

Alright, we have this:

Code Select Expand


group1=['assassin1_1','assassin1_2','assassin1_3']
group2=['assassin2_1','assassin2_2','assassin2_3']
group3=['assassin3_1','assassin3_2','assassin3_3']
group4=['assassin4_1','assassin4_2','assassin4_3']
group5=['assassin5_1','assassin5_2','assassin5_3']
group6=['assassin6_1','assassin6_2','assassin6_3']


And later on this:

Code Select Expand


def repsdown(baddie):
print "rep down"
gd = 0
name = baddie.string
if name in ('thug_bat_dino4', 'thug_bat_dino5', 'thug_bat_dino6', 'dinosaur_thug_gun4', 'dinosaur_thug_gun5', 'dinosaur_thug_gun6'):
rd = Mission_GetAttr('rep_down') + 1
Mission_SetAttr('rep_down',rd)
print rd
if rd == 6:
play(mayor_rescued_cs,'mayor_rescued_cs')
if name in group1:
rd = Mission_GetAttr('assassins1') + 1
Mission_SetAttr('assassins1',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if name in group2:
rd = Mission_GetAttr('assassins2') + 1
Mission_SetAttr('assassins2',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if name in group3:
rd = Mission_GetAttr('assassins3') + 1
Mission_SetAttr('assassins3',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if name in group4:
rd = Mission_GetAttr('assassins4') + 1
Mission_SetAttr('assassins4',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if name in group5:
rd = Mission_GetAttr('assassins5') + 1
Mission_SetAttr('assassins5',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if name in group6:
rd = Mission_GetAttr('assassins6') + 1
Mission_SetAttr('assassins6',rd)
if rd == 3:
gd = Mission_GetAttr('assassingroups') + 1
Mission_SetAttr('assassingroups',gd)
if gd == 6:
Objective_Complete('mayor')
Mission_SetAttr('mayor_saved',1)
speak ('mentor','MISSPCH_4_ME_05a')


Which Always results in this:

Traceback (innermost last):
  File "C:\Documents and Settings\Compaq_Owner\Local Settings\Application Data\Irrational Games\Freedom Force vs the 3rd Reich\temp\mission.py", line 100, in repsdown
    if name in group1:
NameError: group1

[stumpy]

I can't be sure, but it looks like you defined the group variables inside OnPostInit(), which makes their scope local to that function. You probably want to define them outside a function, so that they will be globals and thereby available to other functions in the module.

In other words, instead of

Code Select Expand

def OnPostInit():
...
group1=['assassin1_1','assassin1_2','assassin1_3']
group2=['assassin2_1','assassin2_2','assassin2_3']
group3=['assassin3_1','assassin3_2','assassin3_3']
group4=['assassin4_1','assassin4_2','assassin4_3']
group5=['assassin5_1','assassin5_2','assassin5_3']
group6=['assassin6_1','assassin6_2','assassin6_3']
...
use

Code Select Expand

...
group1=['assassin1_1','assassin1_2','assassin1_3']
group2=['assassin2_1','assassin2_2','assassin2_3']
group3=['assassin3_1','assassin3_2','assassin3_3']
group4=['assassin4_1','assassin4_2','assassin4_3']
group5=['assassin5_1','assassin5_2','assassin5_3']
group6=['assassin6_1','assassin6_2','assassin6_3']

def OnPostInit():
...

You could also use a global declaration in all the functions that use those list variables, but this way is easier.

[catwhowalksbyhimself]

Duh!  Should have realized that!

For future reference, how do you declare a global in python?

[stumpy]

Variables defined at the unindented level of code will be globals for that module and available as readable for any function in the module (and to others that import it), unless they declare a variable of the same name locally.

To write to a global within a function or to declare one there that isn't declared elsewhere at the unindented code level, you declare it as a global using the global keyword (it's actually sort of a preprocessor directive if you are a C coder) in the function before writing to it. In other words,

Code Select Expand

SomeGlobal = 'blarg'
def MyFun1():
    print SomeGlobal
is fine by itslef since it doesn't "write" to the global SomeGlobal.

Code Select Expand

SomeGlobal = 'blarg'
def MyFun1():
    global SomeGlobal
    SomeGlobal = SomeGlobal + ' is a crummy name for a princess.'
def MyFun2():
    print SomeGlobal
The function MyFun2() will print blarg if called before the first and then print blarg is a crummy name for a princess. if called after MyFun1() has been called once. Since MyFun1() changes SomeGlobal, it needs the global declaration.


The global keyword is, for stylistic reasons, usually declared at the top of the function's code block (after any doc text) and used once per variable. But, it can actually take as many arguments as you want to give it and each of them is considered a global. E.g.,

Code Select Expand

def MyFun():
    global glob1
    global glob2
    global glob3
    ...
is functionally the same as

Code Select Expand

def MyFun():
    global glob1, glob2, glob3
    ...
though the former is usually preferred.


There are other details of some interest when declaring/using globals, such as the need with variables that partially pass by reference such as dictionaries and speed issues with local versus global data (local is faster, in those situations where performance is a real issue). Those issues don't come up much in mission scripting. I would guess the Python docs have a pretty good discussion, if you are interested.

[catwhowalksbyhimself]

I definitely need to spend more time in basic Python.

[stumpy]

The tutorial at python.org was very valuable to me, when I started python, way back in '04. Just running through it to see the examples (alongside the FF mission scripts) was great training for the stuff we do here.

[Epimethee]

The tutorial at python.org was very valuable to me, when I started python, way back in '04. Just running through it to see the examples (alongside the FF mission scripts) was great training for the stuff we do here.

Agreed; thanks to Python.org and external resources, the documentation on Python seems very good (not good enough, mind you ;) ). Trying to learn the basics of Pascal made that especially obvious. :/

A few other Python resources:
How to Think Like a Computer Scientist, Python version: http://www.ibiblio.org/obp/thinkCSpy/
A Byte of Python: http://swaroopch.info/text/Byte_of_Python:Main_Page
Learning to Program: http://www.freenetpages.co.uk/hp/alan.gauld/
Dive Into Python: http://diveintopython.org/

I still suggest downloading the (free) Python package from ActiveState.org, rather than the official Python.org version, because it's a bit easier to use due to the included PythonWin editor. The Python.org version has become more Windows-friendly of late, though, and is more up to date; a good companion editor then could be PyScripter: http://mmm-experts.com/Products.aspx?ProductId=4 (Forget editing that fat ffx.py file with it, though.)

Caveat when reading Python documentation: some things won't work if you follow up to date docs, as FF and FFvsTTR use the old 1.5 version of Python (circa 1999). The Python.org docs usually give you the info on compatibility.

[stumpy]

Caveat when reading Python documentation: some things won't work if you follow up to date docs, as FF and FFvsTTR use the old 1.5 version of Python (circa 1999). The Python.org docs usually give you the info on compatibility.

Very good point. http://www.python.org/doc/1.5.2/ (the docs for the python version in the game) is worth bookmarking for anyone doing FF herpetology.