title: Python3: Why i'm getting a UnicodeDecodeError or is this a Memory issue?
body: <p>I'm writing a program to iterate my Robocopy-Log (>25 MB). It's by far not ready, cause I'm stuck with a problem.</p>
  
  <p>The problem is that after iterating ~1700 lines of my log -> I get an "UnicodeError":</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:/Users/xxxxxx.xxxxxx/SkyDrive/#Python/del_robo2.py", line 6, in &lt;module&gt;
      for line in data:
    File "C:\Python33\lib\encodings\cp1252.py", line 23, in decode
      return codecs.charmap_decode(input,self.errors,decoding_table)[0]
  UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 7869: character maps to &lt;undefined&gt;
  </code></pre>
  
  <p>The program looks as follows:</p>
  
  <pre><code>x="Error"
  y=1
  arry = []
  data = open("Ausstellungen.txt",mode="r")
  for line in data:
      arry = line.split("\t")
      print(y)
      y=y+1
      if x in arry:
          print("found")
          print(line)
  data.close()   
  </code></pre>
  
  <p>If I reduce the txt file to 1000 lines then the program works.
  If I delete line 1500 to 3000 and run again, I get again the unicode error around line 1700.</p>
  
  <p>So have I made an error or is this some memory limiting problem of Python?</p>