[NumPy-Tickets] [NumPy] #1566: fmt='%u' in savetxt behaves the same as '%d'.

[NumPy Trac]

#1566: fmt='%u' in savetxt behaves the same as  '%d'.
-------------------------+--------------------------------------------------
 Reporter:  rainwoodman  |       Owner:  somebody
     Type:  defect       |      Status:  new     
 Priority:  normal       |   Milestone:  1.5.0   
Component:  Other        |     Version:  1.4.0   
 Keywords:               |  
-------------------------+--------------------------------------------------
 According to the document of savetxt:
 --------
         ``u`` : unsigned decimal integer
          ``x,X`` : unsigned hexadecimal integer
 --------

 However, the behavior is not as documented:
 {{{
 in [38]: print IDs[0:10]
 -------> print(IDs[0:10])
 [9223372043271415339 9223372043271415853 9223372043271415612
  9223372043271416107 9223372043271415594 9223372043271415836
  9223372043761290139 9223372044088967272 9223372044088967273
  9223372043925949039]
 In [26]: savetxt('/tmp/IDs', IDs, '%u')
 In [27]: !head /tmp/IDs
 -9223372030438136277
 -9223372030438135763
 -9223372030438136004
 -9223372030438135509
 -9223372030438136022
 -9223372030438135780
 -9223372029948261477
 -9223372029620584344
 -9223372029620584343
 -9223372029783602577
 }}}

 The problem is on lib/io.py:1542,
 {{{
     fh.write(format % tuple(row) + '\n')
 }}}

 Apparently python doesn't support '%u' in the '%' operator.

 {{{
 In [44]: '%u', IDs[0]
 Out[44]: ('%u', 9223372043271415339)

 In [45]: print '%u' % IDs[0]
 -------> print('%u' % IDs[0])
 -9223372030438136277
 }}}
 Thus I don't see any easy fix for the problem. What is ironic is that
 IDs[0] is however properly formatted by 'print'.

-- 
Ticket URL: <http://projects.scipy.org/numpy/ticket/1566>
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