numpy.savetxt resulting a formatting mismatch error in python 3.5 : <p>I'm trying to save a numpy matrix (Nx3, float64) into a txt file using numpy.savetxt:</p>

<pre><code>np.savetxt(f, mat, fmt='%.5f', delimiter=' ')
</code></pre>

<p>This line worked in python 2.7, but in python 3.5, I'm getting the following error:</p>

<blockquote>
  <p>TypeError: Mismatch between array dtype ('float64') and format
  specifier ('%.5f %.5f %.5f')</p>
</blockquote>

<p>When I'm stepping into the savetxt code, the print the error (traceback.format_exc()) in the catch block (numpy.lib.npyio, line 1158), the error is completely different:</p>

<blockquote>
  <p>TypeError: write() argument must be str, not bytes</p>
</blockquote>

<p>The line of code resulting the exception is the following:</p>

<pre><code>fh.write(asbytes(format % tuple(row) + newline))
</code></pre>

<p>I tried to remove the asbytes, and it seems to fix this error. Is it a bug in numpy? </p>
