Appendix D — Code topics
This appendix gathers together links to parts of the book that cover various code topics in Python:
- Comments: Note 2.2 and Note 7.2.
 - Variables: Section 4.7.
 - Types of values in Python: Section 7.3.
- Lists in Python: Section 7.3.2.
 - Arrays: Section 7.3.1.
 
 - array length: Section 6.5.
 - Indexing into arrays with integers: Section 6.6.
 - Selecting multiple elements from arrays with slicing: Section 10.2.
 - Strings — values containing text: Section 7.4.
 - Randomness from your computer: Section 2.2.
 - Types of brackets in Python: Note 4.2.
 - Squaring values and arrays: Section 16.7.1.
 - Introducing functions: Section 5.7.
 - Named arguments to functions: Section 5.8.
 - Functions and methods: Note 5.4.
 - Ranges (continuous sequences) of integers: Section 5.9.
 rangein Python (compared tonp.arange): Section 5.10.- Advanced ranges (for example, using floating point values), using 
np.arange: Note 21.7. - Repeating elements of an array with 
np.repeat: Section 7.6} - The absolute function (
np.abs) to convert all values to positive: Note 16.3. forloops: Section 6.6.2.ifstatements: Section 8.10.- Python modules and submodules: Note 12.7.
 - Finding number of repeats using 
np.bincount: Section 11.6 - Combining Boolean arrays with 
&: Section 10.6 rangein Pythonforloops: Section 6.6.3- Testing whether all elements of an array are the same using 
np.all: Note 13.5 - Plotting and histograms (and histogram bins and bin edges): Section 12.15.2.
 - Shuffling arrays with 
rnd.permuted: Section 8.14. - Choosing values at random with 
np.choice: Section 5.11. - Counting 
Truevalues withsum: Section 5.15. - Making arrays by random resampling with 
np.choice: Section 5.12. - Underscores in Python integers: Note 21.5.
 - Building strings with format-strings: Section 21.1.1.
 - What is an operator?: Note 23.2.
 - Logical operators — or, and: Section 23.1.
 - Concatenating arrays: Section 12.15.1.
 - The Comma-Separated-Values (CSV) file format for data tables: Section 16.1.1.
 - Introducing the Pandas Python data science library: Section 16.1.2.