file like objects can be used to read and write tspair and slist

[raciner]

Can now also read and write to file-like objects the same way as the mseed module. Using io.BytesIO comes in handy for example when you use obspy in a web server context. This way, it doesn't need to generate intermediate files on disk.

What does this PR do?

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Why was it initiated? Any relevant Issues?

Please fill in (link relevant issues with "see #123456", mark issues that get resolved with "fixes #12345")

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[megies]

Didn't look at details yet but 👍
One thing that is missing is, if a file like object gets passed in, we need to save and restore the position of the open file pointer in the _is_... method or file format auto-detection breaks as soon as it hit's these I/O plugins here, see last commits in #3370 for what I mean

[megies]

some PEP8 issues (see reviewdog comments inline) and needs to save/restore file position

[raciner]

The code now passes the unit test on my PC except for probable rounding issues

    self.assertEqual(
AssertionError: '185.[15 chars]00043\t185.0299988\t189.0399933\t194.0500031\t205.0599976' != '185.[15 chars]000430000001\t185.02999879999999\t189.03999329[28 chars]9976'
- 185.0099945	181.0200043	185.0299988	189.0399933	194.0500031	205.0599976
?            	           	          ^	          ^
+ 185.0099945	181.02000430000001	185.02999879999999	189.03999329999999	194.0500031	205.0599976
?            	           +++++++	          ^^^^^^^^	          ^^^^^^^^

Not sure whether this is an issue with the code or just a shortcoming in the test.

[megies]

Can you please fix the code formatting before we look at details of test fails, so we can see clearer? Thanks!

PEP8 fails are in the bot comments on the code tab or just run flake8 on command line.

~/git/obspy/obspy｢racin..ter｣$ flake8
./io/ascii/core.py:41:1: F401 'fileinput.filename' imported but unused
./io/ascii/core.py:61:15: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:66:80: E501 line too long (86 > 79 characters)
./io/ascii/core.py:76:28: E231 missing whitespace after ','
./io/ascii/core.py:81:1: W293 blank line contains whitespace
./io/ascii/core.py:83:32: E231 missing whitespace after ','
./io/ascii/core.py:88:28: E231 missing whitespace after ','
./io/ascii/core.py:89:38: E231 missing whitespace after ','
./io/ascii/core.py:97:16: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:102:80: E501 line too long (87 > 79 characters)
./io/ascii/core.py:112:28: E231 missing whitespace after ','
./io/ascii/core.py:117:1: W293 blank line contains whitespace
./io/ascii/core.py:119:32: E231 missing whitespace after ','
./io/ascii/core.py:124:28: E231 missing whitespace after ','
./io/ascii/core.py:125:38: E231 missing whitespace after ','
./io/ascii/core.py:133:17: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:154:24: E231 missing whitespace after ','
./io/ascii/core.py:158:1: W293 blank line contains whitespace
./io/ascii/core.py:176:28: E231 missing whitespace after ','
./io/ascii/core.py:207:18: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:228:24: E231 missing whitespace after ','
./io/ascii/core.py:232:1: W293 blank line contains whitespace
./io/ascii/core.py:250:28: E231 missing whitespace after ','
./io/ascii/core.py:281:26: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:348:24: E231 missing whitespace after ','
./io/ascii/core.py:351:27: E231 missing whitespace after ','
./io/ascii/core.py:352:1: W293 blank line contains whitespace
./io/ascii/core.py:394:28: E231 missing whitespace after ','
./io/ascii/core.py:398:27: F811 redefinition of unused 'filename' from line 41
./io/ascii/core.py:472:24: E231 missing whitespace after ','
./io/ascii/core.py:475:27: E231 missing whitespace after ','
./io/ascii/core.py:476:1: W293 blank line contains whitespace
./io/ascii/core.py:508:28: E231 missing whitespace after ','

[megies]

I'm really sorry, I believe this is done in a more generalized way as part of #3346 which should get merged soon. My bad for not realizing this was already being worked on when you first opened this PR @raciner.

[megies]

I believe this is done now with #3240 merged. Again sorry for overlooking this one for some time.