title: /usr/bin/env: python, No such file or directory
body: <p>I write code working with mapreduce in Ubuntu System in Vmware. Now I have two snippets of code with the same header but one is right and another one report </p>
  
  <pre><code>/usr/bin/env: python  
  : No such file or directory
  </code></pre>
  
  <p>error. This is the one report error:</p>
  
  <pre><code>#!/usr/bin/env python  
  import sys
  if __name__ == '__main__':
      rowNum = 100
      colNum = 100
      for line in sys.stdin:
          type, row, col, val = line.strip().split()
          if type == 'A':
              for k in range(colNum):
                  print '%s,%s\t%s:%s,%s' %  (row, k, type, col, val)
          elif type == 'B':
              for k in range(rowNum):
                  #index1, index2, element = line.split(',')
                  print '%s,%s\t%s:%s,%s' % (k, col, type, row, val)
          else: continue
  </code></pre>
  
  <p>This is correct one. It works well.</p>
  
  <pre><code>#!/usr/bin/env python  
  
  import sys
  
  # input comes from STDIN (standard input) 
  if __name__ == '__main__':
          for line in sys.stdin:
              # remove leading and trailing whitespace  
              line = line.strip()
              # split the line into words  
              words = line.split()
              # increase counters  
              for word in words:
                  # write the results to STDOUT (standard output);  
                  # what we output here will be the input for the  
                  # Reduce step, i.e. the input for reducer.py  
                  #  
                  # tab-delimited; the trivial word count is 1  
                  print '%s\t%s' % (word, 1)
  </code></pre>
  
  <p>I search the whole website and try their method to fix it. But none of them worked, including finding the path is correct or not, checking whether there is a                                     carriage return. I was stun in them whole day because they have the same header but one can not find it.</p>