importing arrays from a file

Coding Python Support
1

hi everyone,

i have a script that exports an array to a file kinda like this:

[[‘NOF’, 0, 0, 0, [], [], []], [60, 1, 3, 6], [62, 9, 11, 13], [64, 13, 14, 21], [‘NOF’]]

using this bit of script:

def save(self,savefile):
  global startstop
  global fname
  print("saving as:")
  print(savefile)
     try:
       f = open(savefile,'w')
       print ("file open")
     except:
       print("unable to save file.")
     try:
       self.writeln(f,self.startstop)
       print("file saved")
       print self.startstop
       f.close()
       print ("file closed")
     except:
       print("cannot save")

def writeln(self,f,x):
  f.write(str(x))
  f.write("
")

and it works fine, but when i try to import the array using this code:

def load(self,loadfile):
  f = open(str(loadfile),'r')
  self.startstop = f.readline()

but it says that the value is out of range.

any sergestions of a better way of importing and exporting the array?

thanks, levon

2

Heyho levon!

Although I don’t see the complete error message and the line where the message appears, I would say that you have to convert self.startstop in load() from a string to the vector you need using string.split() and int() or float() (and maybe some other functions, e.g. list()). The reason for this is that readline() returns a string and you need a list.

Oh, and some advices:

  • You don’t need brackets in print statements
  • Why are there global statements in save()?
3

Addendum (Sorry for the shameless postcount increasing :expressionless: ):

If you only want to access this file from within python you can try the pickle or cpickle module (BUT I dunno if this works inside blender!):


import pickle

.... # your class definitin/methods/members left out, cause I don't know what else you're doing ;-)

    def save(self, filename):
        file = open(filename, 'w')
        pickle.dump(self.startstop, file)
        file.close()

    def load(self, filename):
        file = open(filename, 'r')
        self.startstop = pickle.load(file)
        file.close()

If you need a more complex saving method, you can even look at the shelve module.

HTH

4

pickle and cPickle works perfectly inside Blender.

Martin

5

Thanks, i knew i had to do something like that, but im only new to python and self taught so i dont know much of the python modules, so im learning how to use the split() function now.

Someone sergested that i use pickle, but im making it for the blended midi project and at the moment im trying to keep it so you dont need python to run it.

6

ok, ive worked out a way of importing and export the string using this code:


# import nothing, trust no one
PATH = './test-serial'
DATA = [['NOF',0,0,0,[],[],[],[60,1,2,3],[61,1,2,3],'NOF']]
def Swrite(data,path):
	file = open(path,'w')
	file.write(str(data))
def Sread(path):
	file = open(path,'r')
	lines = file.read()
	output = []
	return recParse(lines)[0]
def parseString(data):
	output = ''
	for i in range(0,len(data)):
		if data[i] == "'":
			return (i +2,output)
		else:
			output = output + data[i]
	raise "Bad error"
			
def parseNum(data):
	output = ''
	for i in range(0,len(data)):
		if data[i] == ",":
			return (i,int(output))
		elif data[i] == ']':
			return (i,int(output))
		else:
			output = output + data[i]
	raise "Bad error"
def recParse(lines):
	output = []
	i = 0
	#for i in range(0,len(lines):
	while i != len(lines):
		if lines[i] == '[':
			l,data = recParse(lines[i+1:]) # if we use 'i', we are in truoble with infinite recursion
			i = i + l -1
			output.append(data)
		elif lines[i] == ']': # finished this list
			return (i+2,output) 
		elif lines[i] == "'": #we have a string
			l,data = parseString(lines[i+1:])
			i = i + l -1
			output.append(data)
		elif lines[i] == ',':
			pass
		elif lines[i] == ' ':
			pass
		#elif i in ['1','2','3','4','5','6','7','8','9',0] : # its a number
		else:
			l,data = parseNum(lines[i:])
			i = i + l -1
			output.append(data)
		i = i + 1
	return output

but when i import it, it says value out of range, when i try to assign the list i import the the one in the script,
any idea why this happens?

7

Can you please post the complete error message, it is a lot easier to find the error when you know the line where it happens. :wink: (I am sooo lazy)

8

after fucking around with it, its now saying "AttributeError: ‘list’ object has no attribute ‘val’ " on the line

self.startstop.val = varsread
9

Is the length of the sublists constant (e.g. the first element [‘NOF’, 0, 0, 0, [], [], []] is always a string, 3 integers and 3 lists) or do you have to handle variable sublists? If it is always constant, you should try string.split() . I recommend you to read the documentation for the string module, it is very helpful. Or as I said before, use pickle.

And pleasepleaseplease post the complete error messages, like:

Traceback (most recent call last):
  File "levon.py", line 71, in ?
    print Sread(sys.argv[1])
  File "levon.py", line 17, in Sread
    return recParse(lines)[0]
  File "levon.py", line 46, in recParse
    l, data = recParse(lines[i+1:]) # if we use 'i', we are in truoble with infinite recursion
  File "levon.py", line 46, in recParse
    l, data = recParse(lines[i+1:]) # if we use 'i', we are in truoble with infinite recursion
  File "levon.py", line 53, in recParse
    l, data = parseString(lines[i+1:])
TypeError: unpack non-sequence
10

May help…

# import nothing, trust no one
PATH = 'g:/tmp/'
DATA = [['NOF',0,0,0,[],[],[],[60,1,2,3],[61,1,2,3],'NOF']]

def writeln(file,data):
    file.write(str(data)+'
')
    
def readAll(file):
    linesarray=file.readlines()
    return linesarray

def create_AnArrayOfArrays(linesarray):
    new_array=[]
    for l in linesarray:
        exec "new_array.append(%s)" % l[:-1]
    return new_array    
    
file=open(PATH+'test.tst','w')
writeln(file,DATA)
writeln(file,DATA)
writeln(file,DATA)
file.close()

file=open(PATH+'test.tst','r')
LINEARRAYS=readAll(file)
NEW_ARRAY=create_AnArrayOfArrays(LINEARRAYS)
print NEW_ARRAY 
for n in NEW_ARRAY:
   for t in n:
       for c in t:
           print c