Sorry, it looks like the answer (as of 2017-09-21) is, "You can't."
The documentation for the python-sdk indicates as much. http://watson-developer-cloud.github.io/python-sdk/v1.0.2/apis/watson_developer_cloud.tone_analyzer_v3.html
See specifically:
Under ToneAnalyzerV3.tone(), parameter tones - you can no longer specify the tone list to return:
tones (list[str]) – 2017-09-21
: Deprecated. The service continues to
accept the parameter for backward-compatibility, but the parameter no
longer affects the response.
Under ToneAnalyzerV3.DocumentAnalysis(), the attribute tones - the service only returns tones with scores of value >= 0.5, which means you can't do your own softmax to exclude analytical:
Attr list[ToneScore] tones:
(optional) 2017-09-21
: An array of ToneScore objects that provides the results of the analysis for each qualifying tone of the
document. The array includes results for any tone whose score is at
least 0.5. The array is empty if no tone has a score that meets this
threshold.
Under ToneAnalyzerV3.SentenceAnalysis(), the attribute tones - same story:
Attr list[ToneScore] tones: (optional) 2017-09-21
: An array of
ToneScore objects that provides the results of the analysis for each
qualifying tone of the sentence. The array includes results for any
tone whose score is at least 0.5. The array is empty if no tone has a
score that meets this threshold.