Use python Decimal for VR of DS about pydicom HOT 3 CLOSED

From [email protected] on May 24, 2009 19:49:40

Thought on how to do this:
In filereader (and similar changes to filewriter):

• change readers mapping for 'DS' to new read_DS() rather than read_string. read_DS
  calls MultiString with Decimal class as type.
• will need to carefully check display when printing dataset or showing its repr
  value. repval used in many display functions may meed tweaking. May need a derived
  class of Decimal to override its repr
• once working, can remove old code that kept the original DS string so could write
  out exactly as read in.

Note -- python decimal module started in python 2.4. This change will probably
require dropping pydicom support for python 2.3, unless there is some other way
around this (perhaps could create own Decimal class that stores the original string,
essentially mimics the current pydicom code). May move to minimum python 2.5 in
future releases anyway.

Owner: ---
Labels: Difficulty-Medium

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From [email protected] on January 04, 2012 19:54:56

Bumping this up in priority, for next release (before python 3 work). Rediscovered a bug that changed values in a multi-value list with VR=DS do not get written to file, e.g.: a statement like ds.PatientImagePositionPatient[2]=9.9 sets data in the dataset object but does not write to the file unless the whole list is replaced with a new list. Switching to using python Decimal class is the best way to solve that bug.

Status: Started
Labels: -Type-Enhancement -Priority-Low -Milestone-Release1.0 Type-Defect Priority-High Milestone-NextRelease

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From [email protected] on January 12, 2012 20:10:15

Fixed in revision c313d2befb08 . DS (and IS) class added and unit tests.

Status: Verified

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