What is "IOError 2"..?

[Jesse.Y]

When I attempted to import a file from a custom made python command I keep getting an IOError 2. What can I do to fix it?

This is what appeared in the script editor:

// Result: scriptEditorPanel1Window|TearOffPane|scriptEditorPanel1|formLayout81|formLayout83|paneLayout6|cmdScrollFieldReporter6 //
from maya import mel
import maya.cmds as cmds

def importSkeleton(fileName):
f = open(fileName,"rb")
f.readline()
f.readline()
f.readline()
numBones = int(f.readline())
bones = []
for i in range(0,numBones):
boneName = f.readline().split()[0]
parent = int(f.readline())
scale = float(f.readline())
matrix = []
matrix.append(f.readline().split())
matrix.append(f.readline().split())
matrix.append(f.readline().split())
bones.append((i,boneName,parent,scale,matrix))
for bone in bones:
cmds.select(d=True)
cmds.joint(p=(float(bone[4][0][3]),float(bone[4][1][3]),float(bone[4][2][3])), n=bone[1]+"_"+str(bone[0]))
for bone in bones:
if bone[2] != -1:
cmds.select(bone[1]+"_"+str(bone[0]))
cmds.select(bones[bone[2]][1]+"_"+str(bones[bone[2]][0]),add=True)
cmds.parent()
editMenuUpdate MayaWindow|mainEditMenu;
python "importSkeleton('C:\\Users\\Jesse.Y\\Tempest.Janna.skl')";
importSkeleton('C:\Users\Jesse.Y\Tempest.Janna.skl')
# Error: IOError: 2 #