Why won't pip install the current version of the package?

Question

I can not get pip to install the current version of pydot (1.0.28). Although yolk and PyPi report this version as available, current,

pip -U pydot

gives me

 Requirement already up-to-date: pydot in /Library/Python/2.7/site-packages Requirement already up-to-date: pyparsing in /Library/Python/2.7/site-packages (from pydot) Requirement already up-to-date: setuptools in /Library/Python/2.7/site-packages (from pydot) 

force current version with

pip -U pydot ==1.0.28

gives me

 Downloading/unpacking pydot==1.0.28 Could not find a version that satisfies the requirement pydot==1.0.28 (from versions: 1.0.2) Some externally hosted files were ignored (use --allow-external to allow). Cleaning up... No distributions matching the version for pydot==1.0.28 

and even

pip -U --allow-external pydot pydot==1.0.28

gives me

 Downloading/unpacking pydot==1.0.28 Could not find a version that satisfies the requirement pydot==1.0.28 (from versions: 1.0.2) Some insecure and unverifiable files were ignored (use --allow-unverified pydot to allow). Cleaning up... No distributions matching the version for pydot==1.0.28 

Answer 1

Try the following:

pip install --allow-unverified pydot pydot==1.0.28