Address the refactor recommendations made by pylint.

[renweizhukov]

$ pylint pytwis
Using config file /home/renwei/repos/github/pytwis/.pylintrc
************* Module pytwis.pytwis_clt
R:124, 0: Too many branches (23/12) (too-many-branches)
R:202, 0: Too many branches (24/12) (too-many-branches)
R:202, 0: Too many statements (62/50) (too-many-statements)
R:362, 0: Too many branches (46/12) (too-many-branches)
R:362, 0: Too many statements (102/50) (too-many-statements)
************* Module pytwis.pytwis
R: 55, 4: Too many arguments (6/5) (too-many-arguments)
R:491, 4: Too many local variables (17/15) (too-many-locals)
R:799, 4: Too many local variables (17/15) (too-many-locals)

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Your code has been rated at 9.87/10 (previous run: 9.87/10, +0.00)