I spent hours researching this vcvarsall.bat as well. Most answers on SO focus on Python 2.7 and / or creating workarounds by modifying system paths. None worked for me. This solution worked out of the box for Python 3.5 and (I think) is the "correct" way of doing it.
See this link -- it describes the Windows Compilers to use for different versions of Python: https://wiki.python.org/moin/WindowsCompilers#Microsoft_Visual_C.2B-.2B-_14.0_standalone:_Visual_C.2B-.2B-_Build_Tools_2015_.28x86.2C_x64.2C_ARM.29
For Python 3.5, download this: https://www.microsoft.com/en-us/download/details.aspx?id=49983
For me, I had to run C:\Program Files (x86)\Microsoft Visual C++ Build Tools\Visual C++ x64 Native Build Tools Command Prompt for it to work. From that command prompt, I ran "pip install django_compressor" which was the particular package that was causing me an issue, and it worked perfectly.
Hope this saves someone some time!