[Numpy-tickets] [NumPy] #663: Support for multi formatting elements in savetxt

[NumPy]

#663: Support for multi formatting elements in savetxt
-------------------------+--------------------------------------------------
 Reporter:  dhuard       |       Owner:  somebody
     Type:  enhancement  |      Status:  new     
 Priority:  normal       |   Milestone:  1.0.5   
Component:  Other        |     Version:  none    
 Severity:  normal       |    Keywords:          
-------------------------+--------------------------------------------------
 Here is a patch to add support for multiple formats in savetxt.
 {{{
 Index: numpy/lib/io.py
 ===================================================================
 --- numpy/lib/io.py     (revision 4815)
 +++ numpy/lib/io.py     (working copy)
 @@ -326,6 +326,10 @@
      the file is automatically saved in compressed gzip format.  The
 load()
      command understands gzipped files transparently.

 +    fmt can be a single format (%10.5f), a sequence of formats, or a
 +    single multi-format string, e.g. 'Iteration %d -- %10.5f', in which
 +    case delimiter is ignored.
 +
      Example usage:

      save('test.out', X)         # X is an array
 @@ -354,8 +358,23 @@
      if len(X.shape)==1:
          origShape = X.shape
          X.shape = len(X), 1
 +
 +    # Fmt can be a string with multiple insertion points or a list of
 formats.
 +    # E.g. '%10.5f\t%10d' or ('%10.5f', '$10d')
 +    if type(fmt) in (list, tuple):
 +        if len(fmt) != X.shape[1]:
 +            raise AttributeError, 'fmt has wrong shape.  '+ str(fmt)
 +        format = delimiter.join(fmt)
 +    elif type(fmt) is str:
 +        if fmt.count('%') == 1:
 +            fmt = [fmt,]*X.shape[1]
 +            format = delimiter.join(fmt)
 +        elif fmt.count('%') != X.shape[1]:
 +            raise AttributeError, 'fmt has wrong number of % formats.  '
 + fmt
 +        else:
 +            format = fmt
      for row in X:
 -        fh.write(delimiter.join([fmt%val for val in row]) + '\n')
 +        fh.write(format%tuple(row) + '\n')

      if origShape is not None:
          X.shape = origShape

 }}}

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Ticket URL: <http://scipy.org/scipy/numpy/ticket/663>
NumPy <http://projects.scipy.org/scipy/numpy>
The fundamental package needed for scientific computing with Python.