Python 2.7 copy file not complete - python-2.7

Question

i am trying to copy a file from a local drive to a Network storage. The file is a TXT file with 6380 lines. Opening the Target file, the copy of the file is not complete, it stops at line 6285 in the middle of the line. The File Itself is a G-Code with 103 kb.
Source File Line 6285: "Z17.168 Y7.393" and the file continues...
Target File Line 6285: "Z17.168 Y7.3" after this its the end of the file.
I tired several differnt copy operations:
from shutil import copyfile
copyfile(WorkDir + FileName, CNCDir + FileName)
or
os.system("copy "+WorkDir + FileName +" " + CNCDir + FileName)
or also the DOS XCOPY command.
The weird thing is, that if i perform the copy command in a separate dos window with the same syntax it works perfect, just by executing it from the PYTHON script, it does not copy the complete file.
Any ideas?

Answer 1

Get a few "debugging" conformation using the following:
Option 1 (blunt reading, should print content to cmd console or editor stdout):
file = open(“testfile.text”, “r”)
print file.read()
Option 2 (reading + loading filecontent into memory, write content from memory to new file):
file = open(“testfile.text”, “r”)
count_lines = 0
counted_lines = 6380
content = []
for line in file:
count_line += 1
content.append(line)
print 'row : "%s" content : "%s"' % (count_lines, file)
if counted_lines == count_lines:
dest_file = open(“new_testfile.txt”,”w”)
for item in content:
dest_file.write(item)
dest_file.close()
else:
print 'error at line : %s' % count_lines
Option 3 (excludet character issue at line 6285 and show its a memory loading issue):
from itertools import islice
# Print the "6285th" line.
with open(“testfile.text”) as lines:
for line in islice(lines, 6284, 6285):
print line
Option 4 is found here.
and
Option 5 is:
import linecache
linecache.getline(“testfile.text”, 2685)

Answer 2

Using Option 1 on the target file gives me:
Z17.154 Y7.462
Z17.159 Y7.439
Z17.163 Y7.416
Z17.168 Y7.3
"done"
Press any key to continue . . .
Using Option 2 gives:
row : "6284" content : "<open file 'Z:\\10-Trash\\APR_Custom.SPF', mode 'r' at 0x0000000004800AE0>"
row : "6285" content : "<open file 'Z:\\10-Trash\\APR_Custom.SPF', mode 'r' at 0x0000000004800AE0>"
And a TXT File with the same content like the Target file:
Last 3 lines:
Z17.159 Y7.439
Z17.163 Y7.416
Z17.168 Y7.3
I tried option 4 -6 aswell but i dont see a purpose behind that. With Option 5 I had to change the line numbe to 6284 because list was out of range with that number.
from itertools import islice
# Print the "6285th" line.
with open(CNCDir + FileName) as lines:
for line in islice(lines, 6284, 6285):
print "Option 3:"
print line
f=open(CNCDir + FileName)
lines=f.readlines()
print "Option 4:"
print lines[6284]
import linecache
print "Option 5:"
print linecache.getline(CNCDir + FileName, 6285)
Out file from Command line:
Copy to CNC:
Source: C:\F-Engrave\WorkDir\APR_Custom.SPF
Traget: Z:\10-Trash\APR_Custom.SPF
Option 3:
Z17.168 Y7.3
Option 4:
Z17.168 Y7.3
Option 5:
Z17.168 Y7.3
"done"
Press any key to contiune. . .