named tuples

[Mekire]

Well, there doesn't seem to be a way to get the names of the fields from it directly, but they are always in the same order so you can build a dict easily as I showed in the previous post.

[Skaperen]

Well, there doesn't seem to be a way to get the names of the fields from it directly, but they are always in the same order so you can build a dict easily as I showed in the previous post.

i really didn't understand your post.  i don't even understand this one.  you are saying it can't be done but your code does it easily?  to build a dict you need to get the keys.  how do you get the keys?   apparently we can't use vars(").  do you know of anything simpler than:

Output:
lt1/forums /home/forums 12> py3
Python 3.5.2 (default, Nov 17 2016, 17:05:23) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> [x.split('=')[0] for x in repr(sys.version_info).split('(')[1].split(')')[0].split(', ')]
['major', 'minor', 'micro', 'releaselevel', 'serial']
>>>

which is the kind of "parsing" i was referring to.

[Mekire]

I'm saying the "keys" are always the same for a sys.version_info object. So if you have such an object you just zip the values with the known "keys".

>>> import sys
>>> fields = ["major", "minor", "micro", "releaselevel", "serial"]
>>> dict(zip(fields, sys.version_info))
{'micro': 11, 'major': 2, 'releaselevel': 'final', 'serial': 0, 'minor': 7}

You don't need to parse out the keys if you already know what they are...
Now I have a dict of those keys to their values and can do whatever I want with it.

[Skaperen]

i won't know what they (the keys) are until i figure out the object the caller provides.  i've seen another object like this before.  then i need to see what else my code might run across.

[Skaperen]

is time.struct_time a named tuple?

Output:
lt1/forums /home/forums 1> py2
Python 2.7.12 (default, Nov 19 2016, 06:48:10) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import time
>>> print(repr(time.gmtime()))
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=5, tm_hour=2, tm_min=43, tm_sec=5, tm_wday=4, tm_yday=125, tm_isdst=0)
>>> 
lt1/forums /home/forums 2> py3
Python 3.5.2 (default, Nov 17 2016, 17:05:23) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import time
>>> print(repr(time.gmtime()))
time.struct_time(tm_year=2017, tm_mon=5, tm_mday=5, tm_hour=2, tm_min=43, tm_sec=28, tm_wday=4, tm_yday=125, tm_isdst=0)
>>> 
lt1/forums /home/forums 3>

[Larz60+]

It is very similar, but not exactly the same as the C structure tm.
There are differences such as tm_year, the value in python is the actual year, not
year -1900.

The official desctiption is:

The time value as returned by gmtime(), localtime(), and strptime(), and
accepted by asctime(), mktime() and strftime().  May be considered as a
sequence of 9 integers.

Note that several fields' values are not the same as those defined by
the C language standard for struct tm.  For example, the value of the
field tm_year is the actual year, not year - 1900.  See individual
fields' descriptions for details.

You can get full field descriptions in an interactive session by:
importing time
and calling help(''time.struct_time')

[Skaperen]

my concern is how to deal with these things that look like tuples in my print_object() function and other similar things in other projects.  i guess i will apply my other tests and use repr() on things that don't match up to that point.  at things like time.localtime() and sys.version_info() fail the instance(,tuple) test so i can apply repr() to them.  my goal is to output reconstructive source code.  there is a way (call the class with a list of values) to reconstruct time.struct_time (so i need to test for this and handle it as a special case) but not sys.version_info. so they are not alike types.

see: https://python-forum.io/Thread-printobject-py

[Larz60+]

why look beyond the built-in?

def zingo():
   return 1, 2, 3
print('zingo: {}'.format(zingo()))

results:

Output:
zingo: (1, 2, 3)

[Skaperen]

...to get something that produces the correct output.  the format method does not.  adding the zingo function has no effect in that case.

[Larz60+]

The format statement can be controlled same as printf in C.
The arguments are almost (perhaps exact, I have never checked) as C,
s for string, f for float, etc. individual cells precision etc can all be controlled.
FYI zingo had nothing to do with previous post, other than to serve a tuple.