Exercise_File_E-SASPy_Convenience_Methods.py

# Everything is better with friends: Executing SAS® code in Python scripts with
# SASPy, and turbocharging your SAS programming with open-source tooling
#
# Half-day class, Western Users of SAS Software (WUSS) 2019


###############################################################################
# Exercises 11-12: SASPy Convenience Methods                                  #
###############################################################################

# Lines 12-14 load modules needed for exercises and should be left as-is
from class_setup import print_with_title
from saspy import SASsession
sas = SASsession()




###############################################################################
#                                                                             #
# Exercise 11. [Python w/ saspy] Connect directly to a SAS dataset            #
#                                                                             #
# Instructions: Uncomment the code immediately below, and then execute        #
#                                                                             #
###############################################################################


# fish_sds = sas.sasdata(table='fish', libref='sashelp')
# print_with_title(type(fish_sds), 'The type of fish_sds:')
# print_with_title(
#     fish_sds.columnInfo(),
#     'The Python equivalent of PROC CONTENTS:'
# )
# print_with_title(fish_sds.means(), 'The Python equivalent of PROC MEANS:')


# Notes:
# 1. The SASdata object fish_sds (meaning a direct connection to the disk-based
#    SAS dataset sashelp.fish, not an in-memory DataFrame) is created, and the
#    following are printed:
#    * the type of object fish_sds
#    * the column-information portion of PROC CONTENTS applied to the SAS
#      dataset sashelp.fish
#    * summary information about the 7 columns in sashelp.fish
#
# 2. The sas object, which was created at the beginning of this file, is a
#    persistent connection to a SAS session, and its sasdata method is used to
#    create the connection to sashelp.fish.
#
# 3. The fish_sds object calls its convenience method means, which implicitly
#    invokes PROC MEANS on sashelp.fish.
#
# 4. All subsequent exercises in this file will assume the object fish_sds
#    exists, so please don't comment out the line creating it.
#
# 5. For additional practice, try out the additional convenience methods at
#    https://sassoftware.github.io/saspy/api.html#sas-data-object.




###############################################################################
#                                                                             #
# Exercise 12. [Python w/ saspy] Get convenience method SAS code              #
#                                                                             #
# Instructions: Uncomment the code immediately below, and then execute        #
#                                                                             #
###############################################################################


# sas.teach_me_SAS(True)
# print_with_title(
#     '',
#     'The SAS code generated by fish_sds.means():',
#     linebreaks_after=0,
#     put_stars_after=False
# )
# fish_sds.means()
# print_with_title('', '', linebreaks_before=0, linebreaks_after=0)
# sas.teach_me_SAS(False)


# Notes:
# 1. The SASdata object fish_sds, which was created in an exercise above as a
#    direct connection to the SAS dataset sashelp.fish, calls its convenience
#    method means within a "Teach Me SAS" sandwich, and the following is
#    printed:
#    * the SAS code for the PROC MEANS step implicitly generated by the means
#      convenience method
#
# 2. The sas object, which was created at the beginning of this file, is a
#    persistent connection to a SAS session, and its teach_me_SAS method is
#    used as follows:
#    * When called with argument True, SAS output is suppressed for all
#      subsequent saspy convenience methods, and the SAS code generated is
#      returned instead.
#    * When teach_me_SAS is called with argument False, this behavior is turned
#      off.
# 3. True and False are standard Python objects. Like their SAS equivalents,
#    they are interchangeable with the values 1 and 0, respectively.
#
# 4. One benefit of this process is being able to extract and modify the SAS
#    code. For example, if a convenience method doesn't offer an option like a
#    class statement for PROC MEANS, we can manually add it to the code
#    generated by the teach_me_SAS method and then execute the modified SAS
#    code using the submit method.
#
# 5. For additional practice, try getting the SAS code for other methods at
#    https://sassoftware.github.io/saspy/api.html#sas-data-object.