DA, DT, TM converters

[darcymason]

From Dimitri....@gmail.com on April 18, 2014 20:11:27

As suggested in discussion "TM, DA converters?" tags DA, DT, TM could be converted to datetime objects: https://groups.google.com/forum/#!topic/pydicom/4IMwZiFgCkk

Original issue: http://code.google.com/p/pydicom/issues/detail?id=142

[darcymason]

From Dimitri....@gmail.com on April 18, 2014 17:16:47

Please find a proof-of-concept here: https://code.google.com/r/dimitripapadopoulos-pydicom/source/detail?r=11dac0718ead057e40108337096c22f3c4d0b8a4 For now tested on a pair of DICOM files only. Just wanted some feedback before adding comments and testing more extensively.

[darcymason]

From Dimitri....@gmail.com on April 18, 2014 17:17:56

Significant additional dependencies:
re
dateutil.tz

[darcymason]

From Dimitri....@gmail.com on April 27, 2014 06:10:13

I have a new version with a dicom.config.datetime_conversion switch to toggle between previous behavior and conversion to datetime objects. https://code.google.com/r/dimitripapadopoulos-pydicom/source/detail?r=92da991a405fa8c9e16c6147ba32160eeaacfdcb Any additional changes?

[darcymason]

From darcymason@gmail.com on April 28, 2014 18:42:57

Looks good. Adding unit tests would be much appreciated, for some normal values and for some corner cases. Also I didn't notice anything yet on the writing side -- the existing "round-trip" read/write unit tests (a couple of files maybe) could be copied to do tests with the config conversion on.

[darcymason]

From Dimitri....@gmail.com on May 01, 2014 03:44:49

I have added unit tests and documentation: https://code.google.com/r/dimitripapadopoulos-pydicom/source/detail?r=7aa18b660782182d6e72564185f796abeae9ef52 Which are the "round-trip" read/write tests to run with the config conversion on?

[darcymason]

From Dimitri....@gmail.com on May 01, 2014 06:16:16

And by the way, I must admit I'm not sure what needs to be added on the writing side. A standalone function to create a data element from a datetime object? But that's not in the filewriter code, is t?

[darcymason]

From Dimitri....@gmail.com on May 02, 2014 01:19:49

I seldom use the part of pydicom that writes DICOM files. I've spent a few hours on it and I think I have understood enough of it:

• to add a test by merely inheriting WriteFileTests,
• to fix dataelem.py so that DA, DT, TM data elements are still created as strings if datetime_conversion is not set.

I'm not sure I'm doing the right thing when it comes to initializing data elements from datetime objects - see the new() method of DA, DT, TM classes.

[darcymason]

From darcymason@gmail.com on May 07, 2014 06:37:47

Hi Dimitri,
I've had a look through the code and everything looks good. I'll pull it into my local clone and go through it in more detail.

[darcymason]

From agrothberg on November 09, 2014 13:09:56

What ever came of this patch / addition?

[DimitriPapadopoulos]

Would a Git branch forked from current dev branch help moving forward?

[darcymason]

Yes that would be very helpful. Thanks.

[cancan101]

Any chance of getting this merged for the v1 release?

[PhySci]

Hi everyone,
Does DA, DT, TM converter work in the current release?

[DimitriPapadopoulos]

It should work, yes. Any specific issue?

[DimitriPapadopoulos]

Note that you need to set config.datetime_conversion first.

[PhySci]

Many thanks for the reply.
I set datetime_conversion , read an MRI file:

import dicom
dicom.config.datetime_conversion = True

img = dicom.read_file('example.dcm')
img

and saw that DA and TM properties are still strings, like '20001106'.

Have I missed something?

[DimitriPapadopoulos]

Are the DA and TM properties actual strings, or are they DA TM objects interpreted/printed as strings in a certain context?

[PhySci]

type(img.data_element('AcquisitionDate').value) returns 'str'

[DimitriPapadopoulos]

Indeed, using the default pydicom on my account with Ubuntu 16.04 (with NeuroDebian):

>>> import dicom
>>> dicom.config.datetime_conversion = True
>>> dataset = dicom.read_file('example.dcm')
>>> dataset.AcquisitionDate
'20170101'
>>> type(dataset.AcquisitionDate)
<type 'str'>
>>> 

I would need to double-check which version I'm using, which one is provided by the system and/or NeuroDebian, etc. Unfortunately I won't have time in the short term. If anyone knows about it...

[DimitriPapadopoulos]

The latest release is 0.9.9.post1.

The datetime_conversion mechanism should appear in release 1.0.0, whenever it is released.

[mrbean-bremen]

Shall be fixed now with the release.