The Python Journeyman

Table of Contents......Page 3
Errata and Suggestions......Page 8
Conventions Used in This Book......Page 9
Welcome Journeyman!......Page 12
Built­-in types: Integers, Floats, Strings, Lists, Dictionaries and Sets......Page 13
Defining classes with methods......Page 14
Unit testing, debugging and deployment......Page 15
Well begun is half done......Page 16
Packages......Page 17
Implementing packages......Page 23
Relative imports......Page 31
__all__......Page 34
Namespace packages......Page 36
Executable directories......Page 38
Executable packages......Page 41
Recommended layout......Page 44
Modules are singletons......Page 45
Summary......Page 46
Review of Functions......Page 49
Functions as callable objects......Page 50
Callable instances and the __call__() method......Page 51
Classes are Callable......Page 55
Leveraging callable classes......Page 56
Lambdas......Page 58
Detecting Callable Objects......Page 60
Extended Formal Parameter Syntax......Page 62
Extended Call Syntax......Page 70
Transposing Tables......Page 72
Summary......Page 76
Local functions......Page 78
Closures and nested scopes......Page 82
Function decorators......Page 90
Validating arguments......Page 103
Summary......Page 105
Class attributes......Page 107
Static methods......Page 112
Class methods......Page 114
Named constructors......Page 115
Overriding static- and class-methods......Page 118
Properties......Page 124
Overriding properies......Page 134
The template method pattern......Page 142
Summary......Page 145
Two string representations......Page 146
Strings for developers with repr()......Page 147
Strings for clients with str()......Page 148
When are the representation used?......Page 149
Precise control with format()......Page 151
Leveraging reprlib for large strings......Page 154
The ascii(), ord() and chr() built-in functions......Page 155
Case study: String representations of tabular data......Page 157
Summary......Page 159
Python's basic numeric types......Page 162
The limits of floats......Page 164
The decimal module......Page 166
The fractions module......Page 176
Complex Numbers......Page 178
Built-in functions relating to numbers......Page 184
Dates and times with the datetime module......Page 188
Case study: Rational numbers and computational geometry......Page 201
Summary......Page 231
Review of comprehensions......Page 233
Multi-input comprehensions......Page 234
map()......Page 239
filter()......Page 246
functools.reduce()......Page 248
Combining functional concepts: map-reduce......Page 251
The iteration protocols......Page 253
Case study: an iterable and iterator for streamed sensor data......Page 258
Summary......Page 260
Single inheritance......Page 263
Type inspection......Page 268
Multiple inheritance......Page 272
MRO: Method Resolution Order......Page 275
super()......Page 279
object......Page 287
Summary......Page 289
Collection protocols......Page 293
Test first......Page 294
The initializer......Page 295
The container protocol......Page 297
The sized protocol......Page 299
The iterable protocol......Page 302
The sequence protocol......Page 304
The set protocol......Page 326
Summary......Page 333
Exception dangers......Page 335
Exceptions hierarchies......Page 339
Exception payloads......Page 343
User-defined exceptions......Page 347
Exception chaining......Page 350
Tracebacks......Page 355
Assertions......Page 356
Preconditions, postconditions and assertions......Page 361
Summary......Page 370
What is a context manager?......Page 372
The context manager protocol......Page 374
contextlib.contextmanager......Page 384
Multiple context-managers in a with-statement......Page 388
Context managers for transactions......Page 393
Summary......Page 396
Introspecting types......Page 399
Introspecting objects......Page 401
Introspecting scopes......Page 405
The inspect module......Page 408
An object introspection tool......Page 413
Summary......Page 424
Afterword: Levelling Up......Page 426
Appendix A - Python implementation of ISO6346......Page 428