Adding a field to a structured numpy array (2)

python numpy recarray
joris picture joris · Mar 13, 2011 · Viewed 15.2k times · Source

I know there was already a question about this topic (cleanest way to add a field to a structured numpy array), see

Adding a field to a structured numpy array

but I have a question about the answer given there ...

If you're using numpy 1.3, there's also numpy.lib.recfunctions.append_fields()

I still have numpy 1.3, but it doesn't recognise this function, and I also didn't find anything about it in the documentation of numpy. What happened with the function? Is there another function that can do the same?

Answer

dting picture dting · Mar 13, 2011

http://projects.scipy.org/numpy/browser/branches/1.3.x/numpy/lib/recfunctions.py?rev=8229

did you import?

from numpy.lib import recfunctions

recfunctions.append_fields(*your_args)  # base, names, data, ...

Seems like everything is working:

Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy
>>> numpy.__version__
'1.3.0'
>>> from numpy.lib.recfunctions import append_fields
>>> append_fields
<function append_fields at 0x9e3e80c>
>>>

Related questions

Sorting a python array/recarray by column

I have a fairly simple question about how to sort an entire array/recarray by a given column. For example, given the array: import numpy as np data = np.array([[5,2], [4,1], [3,6]]) I would like to sort data by the first column …

Read More
Convert structured array to regular NumPy array

The answer will be very obvious I think, but I don't see it at the moment. How can I convert a record array back to a regular ndarray? Suppose I have following simple structured array: x = np.array([(1.0, 4.0,), (2.0, -1.0)], dtype=[(…

Read More
Convert pandas dataframe to NumPy array

I am interested in knowing how to convert a pandas dataframe into a NumPy array. dataframe: import numpy as np import pandas as pd index = [1, 2, 3, 4, 5, 6, 7] a = [np.nan, np.nan, np.nan, 0.1, 0.1, 0.1, 0.1] b = [0.2, np.nan, 0.2, 0.2, 0.2, np.nan, np.nan] c = […

Read More