Python 2.4 Compatibility

[kujaku11]

I've had a bug report from a potential user that MTpy is not compatible with Python 2.4 or 2.5. It doesn't seem like a huge deal to make it 2.4 compatible (see error list below, mostly change with statement and logic syntax in lists) just some syntax changes. The questions is should we fork a branch that is compatible with 2.4 which will be compatible with 2.x or always use 2.4 syntax, which defeats some the great things about current Python versions. Any thoughts? I made a branch called Python_v_2.4 as a start to see how much work it would be. I'm also not positive about how compatible some of the major packages (Numpy, Scipy, Matplotlib, etc) we use are backwards compatible to 2.4.

running install
running build
running build_py
running build_scripts
running install_lib
byte-compiling /usr/lib/python2.4/site-packages/mtpy/utils/misc.py to misc.pyc
File "/usr/lib/python2.4/site-packages/mtpy/utils/misc.py", line 145
class MemoryCheck():
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/utils/configfile.py to configfile.pyc
File "/usr/lib/python2.4/site-packages/mtpy/utils/configfile.py", line 119
with open(filename) as F:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/utils/remove_instrumentresponse_from_files.py to remove_instrumentresponse_from_files.pyc
File "/usr/lib/python2.4/site-packages/mtpy/utils/remove_instrumentresponse_from_files.py", line 81
lo_channels = list(set([i.upper() if len(i)==2 else 'B'+i.upper() for i in sys.argv[4].split(',')]))
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/utils/convert_coordinates_in_edis.py to convert_coordinates_in_edis.pyc
File "/usr/lib/python2.4/site-packages/mtpy/utils/convert_coordinates_in_edis.py", line 78
with open(infile,'r') as F:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/utils/filehandling.py to filehandling.pyc
File "/usr/lib/python2.4/site-packages/mtpy/utils/filehandling.py", line 578
with open(tsfile,'r') as F:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/test/utils.py to utils.pyc
File "/usr/lib/python2.4/site-packages/mtpy/test/utils.py", line 40
with open(i,'r') as f:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/test/basic.py to basic.pyc
File "/usr/lib/python2.4/site-packages/mtpy/test/basic.py", line 23
with self.assertRaises(ValueError):
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/analysis/distortion.py to distortion.pyc
File "/usr/lib/python2.4/site-packages/mtpy/analysis/distortion.py", line 345
lo_dims = [ 4 if i == 1 else i for i in lo_dims ]
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/analysis/pt.py to pt.pyc
File "/usr/lib/python2.4/site-packages/mtpy/analysis/pt.py", line 922
class ResidualPhaseTensor():
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/processing/birrp.py to birrp.pyc
File "/usr/lib/python2.4/site-packages/mtpy/processing/birrp.py", line 239
with open(string_file,'w') as F:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/processing/io.py to io.pyc
File "/usr/lib/python2.4/site-packages/mtpy/processing/io.py", line 58
with open(filename, 'r') as f:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/modeling/occam1d.py to occam1d.pyc
File "/usr/lib/python2.4/site-packages/mtpy/modeling/occam1d.py", line 1803
class PlotL2():
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/modeling/occam2d.py to occam2d.pyc
File "/usr/lib/python2.4/site-packages/mtpy/modeling/occam2d.py", line 73
class Setup():
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/core/edi.py to edi.pyc
File "/usr/lib/python2.4/site-packages/mtpy/core/edi.py", line 176
with open(infile,'r') as F:
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/usgs/zonge.py to zonge.pyc
File "/usr/lib/python2.4/site-packages/mtpy/usgs/zonge.py", line 34
class ZongeMTFT():
^
SyntaxError: invalid syntax
byte-compiling /usr/lib/python2.4/site-packages/mtpy/usgs/zen.py to zen.pyc
File "/usr/lib/python2.4/site-packages/mtpy/usgs/zen.py", line 2137
class ZenBIRRP():
^
SyntaxError: invalid syntax
running install_scripts
changing mode of /usr/bin/ws2vtk.py to 755

[kinverarity1]

For background information: in the past 18 months, numpy, scipy, and matplotlib have all dropped support for Python < 2.6. Numpy did it as of Oct 2013 with 1.8; scipy did it in April 2013 with 0.12; and matplotlib in Nov 2012 with 1.2. So far as I understand they did so in order to support Python 3+, which I imagine mtpy is unable to run on. I would suggest making the changes to support Python 2.4 & 2.5 in the master branch, and instead maintaining/working on Python 3+ compatibility (i.e. minimum python 2.6 requirement) in a branch. That's how every pretty much every other project I've seen is managing the transition.

[kinverarity1]

Changes to look out for are here:
http://docs.python.org/2/whatsnew/2.5.html
http://docs.python.org/2/whatsnew/2.6.html

Also I've been looking through some of those errors:

1. sets are inbuilt types in >2.6, but live in the sets standard library module in <2.6
2. with statements were unfortunately only introduced in 2.5
3. inline if statements (5 if x == 2 else 10) were only introduced in 2.5

I'm not sure what the class errors are about.

[kujaku11]

Thanks for that Kent. So who wants to make the changes? For the most part they look relatively easy. I also don't know about the class errors.

[hugovk]

[3.5 years later...]

Is Python 2.4 still needed? Many packages are now dropping 2.6.