Reading File Into 2D List

[alex.hanga]

Hello!

I'm new here and fairly new to Python. I am attempting to read a data file into python and adding it to a 2D list to make it easy to use further down the line.

My data file is just 7 numbers in a row seperated by commas and each bulk of data is seperated by the sign @ to indicate that the data from this pointon should be stored into a new part of the 2D list.

1,1,1,1,1,1,1
2,2,2,2,2,2,2
@
3,3,3,3,3,3,3
4,4,4,4,4,4,4

After reading the file, the way I imagine the data to be shown would be in this manner:

data[0][0] = (1,1,1,1,1,1,1)
data[0][1] = (2,2,2,2,2,2,2)
data[1][0] = (3,3,3,3,3,3,3)
data[1][1] = (4,4,4,4,4,4,4)

This way it will be easy to loop across the data when I use it in Blender.

My code looks like this;

------------------------------
object_data = []
object_data.append([])

for rows in data.splitlines():
elems = rows.split(',')
if elems[0] != "@":
object_data.append((float(elems[0]),float(elems[1]),
float(elems[2]),float(elems[3]),float(elems[4]),
float(elems[5]),int(elems[6])))
else:

**start on object_data[1][j] and loop over it all again**

 

[Dave Angel]

Hello!

I'm new here and fairly new to Python. I am attempting to read a data file into python and adding it to a 2D list to make it easy to use further down the line.

My data file is just 7 numbers in a row seperated by commas and each bulk of data is seperated by the sign @ to indicate that the data from this point on should be stored into a new part of the 2D list.

1,1,1,1,1,1,1
2,2,2,2,2,2,2
@
3,3,3,3,3,3,3
4,4,4,4,4,4,4

Perhaps you mean:
data = """\
1,1,1,1,1,1,1
2,2,2,2,2,2,2
@
3,3,3,3,3,3,3
4,4,4,4,4,4,4
"""

After reading the file, the way I imagine the data to be shown would be in this manner:

data[0][0] = (1,1,1,1,1,1,1)
data[0][1] = (2,2,2,2,2,2,2)
data[1][0] = (3,3,3,3,3,3,3)
data[1][1] = (4,4,4,4,4,4,4)

perhaps you mean:
object_data[0][0] == (1,1,1,1,1,1)
etc.

This way it will be easy to loop across the data when I use it in Blender.

My code looks like this;

You omitted i = 0

for rows in data.splitlines():

So exactly what is data? It's not what you say above. Did you get it
by doing something like myfile.read() ?

elems = rows.split(',')
if elems[0] != "@":
object_data.append((float(elems[0]),float(elems[1]),
float(elems[2]),float(elems[3]),float(elems[4]),
float(elems[5]),int(elems[6])))
else:

**start on object_data[1][j] and loop over it all again**
-------------------------------

I could really use some help as to how I would force my code to not start on object_data[0] on the next iteration in the for loop, but rather on object_data[1]. I'm an avid Matlab user so I imagined this to be done simply by setting i=i+1 in the else part, however this does not work as it complains about the list being out of bounds.

Any help is really appreciated!

Replace te **start line with something like:

object_data.append([])
i += 1

This assumes a few missing lines, which must have been there or you
would have already had runtime errors. For example, you'll need i=0
before the loop.

Another comment about the append with all those calls to float(). When
you see a line like that, you want to seriously consider making it a
loop, or a comprehension, or something.

Given that elem is a list of strings, you could convert it to a list of
float, then convert that to a tuple (if you really wanted that). At
that point, you just append it. All this could be done in one line if
you like, something like (untested):

object_data.append(tuple(map(float, row.split(","))))

 

[alex.hanga]

Replace te **start line with something like:

object_data.append([])

i += 1



This assumes a few missing lines, which must have been there or you

would have already had runtime errors. For example, you'll need i=0

before the loop.



Another comment about the append with all those calls to float(). When

you see a line like that, you want to seriously consider making it a

loop, or a comprehension, or something.



Given that elem is a list of strings, you could convert it to a list of

float, then convert that to a tuple (if you really wanted that). At

that point, you just append it. All this could be done in one line if

you like, something like (untested):



object_data.append(tuple(map(float, row.split(","))))

Yes, indeed there are a few lines missing. Just the read file and the i=0pretty much. The help you gave me solved my problem, thank you very much!

I know the calls to float() are sub par and quite stupidly made but I'm notthat good at python scripting (yet) so I try to keep my functions rather easy to read so I understand what is happening. A bit later I will take the time to make my code more sophisticated, but as of now I just want it to work, hehe.

Again, thank you so much!