Perhaps you should try some spelling variations:
"an introduction python python programming" » "an introduction section python programming" (Expand search), "an introduction earthen python programming" (Expand search), "an introduction methods python programming" (Expand search), "an introduction pythons python programming" (Expand search), "an introduction piton python programming" (Expand search), "an introduction pitons python programming" (Expand search)
"based coding _ decoding program" » "based coding _ welcoming program" (Expand search), "based coding _ deworming program" (Expand search), "based coding _ feeding program" (Expand search), "based costing _ decoding program" (Expand search), "based coating _ decoding program" (Expand search), "based coatings _ decoding program" (Expand search)

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"based coding _ decoding program\") OR (\"an introduction python python programming\"))~".
• Removing quotes may allow a broader search: (( based coding _ decoding program ) OR ( an introduction python python programming ))~.
• Adding a wildcard symbol may retrieve word variants: (("based coding _ decoding program") OR ("an introduction python python programming"))*.