An interesting collection of surprising snippets and lesser-known Python features.
+An interesting collection of surprising snippets and lesser-known Python features.
[![WTFPL 2.0][license-image]][license-url] @@ -77,7 +77,7 @@ So, here we go... - [▶ Yes, it exists!](#-yes-it-exists) - [▶ Inpinity *](#-inpinity-) - [▶ Mangling time! *](#-mangling-time-) - - [Section: Miscallaneous](#section-miscallaneous) + - [Section: Miscellaneous](#section-miscellaneous) - [▶ `+=` is faster](#--is-faster) - [▶ Let's make a giant string!](#-lets-make-a-giant-string) - [▶ Explicit typecast of strings](#-explicit-typecast-of-strings) @@ -97,22 +97,22 @@ All the examples are structured like below: > ### ▶ Some fancy Title * > The asterisk at the end of the title indicates the example was not present in the first release and has been recently added. -> +> > ```py > # Setting up the code. > # Preparation for the magic... > ``` -> +> > **Output (Python version):** > ```py > >>> triggering_statement > Probably unexpected output > ``` > (Optional): One line describing the unexpected output. -> -> +> +> > #### 💡 Explanation: -> +> > * Brief explanation of what's happening and why is it happening. > ```py > Setting up examples for clarification (if necessary) @@ -241,7 +241,7 @@ some_dict[5] = "Python" True ``` **Note:** Objects with different values may also have same hash (known as hash collision). -* When the statement `some_dict[5] = "Python"` is executed, the existing value "JavaScript" is overwritten with "Python" because Python recongnizes `5` and `5.0` as the same keys of the dictionary `some_dict`. +* When the statement `some_dict[5] = "Python"` is executed, the existing value "JavaScript" is overwritten with "Python" because Python recognizes `5` and `5.0` as the same keys of the dictionary `some_dict`. * This StackOverflow [answer](https://stackoverflow.com/a/32211042/4354153) explains beautifully the rationale behind it. --- @@ -1135,7 +1135,7 @@ str and type(other) is SomeClass and super().__eq__(other) ) - + # When we define a custom __eq__, Python stops automatically inheriting the # __hash__ method, so we need to define it as well __hash__ = str.__hash__ @@ -1313,7 +1313,7 @@ Shouldn't that be 100? > First, tabs are replaced (from left to right) by one to eight spaces such that the total number of characters up to and including the replacement is a multiple of eight <...> * So the "tab" at the last line of `square` function is replaced with eight spaces, and it gets into the loop. * Python 3 is kind enough to throw an error for such cases automatically. - + **Output (Python 3.x):** ```py TabError: inconsistent use of tabs and spaces in indentation @@ -1697,7 +1697,7 @@ a += [5, 6, 7, 8] * The expression `a = a + [5,6,7,8]` generates a new list and sets `a`'s reference to that new list, leaving `b` unchanged. -* The expression `a + =[5,6,7,8]` is actually mapped to an "extend" function that operates on the list such that `a` and `b` still point to the same list that has been modified in-place. +* The expression `a += [5,6,7,8]` is actually mapped to an "extend" function that operates on the list such that `a` and `b` still point to the same list that has been modified in-place. --- @@ -1731,7 +1731,7 @@ UnboundLocalError: local variable 'a' referenced before assignment a += 1 return a ``` - + **Output:** ```py >>> another_func() @@ -2127,7 +2127,7 @@ Why did `Yo()._Yo__honey` worked? Only Indian readers would understand. --- -## Section: Miscallaneous +## Section: Miscellaneous ### ▶ `+=` is faster @@ -2272,7 +2272,7 @@ nan ### ▶ Minor Ones * `join()` is a string operation instead of list operation. (sort of counter-intuitive at first usage) - + **💡 Explanation:** If `join()` is a method on a string then it can operate on any iterable (list, tuple, iterators). If it were a method on a list, it'd have to be implemented separately by every type. Also, it doesn't make much sense to put a string-specific method on a generic `list` object API. @@ -2369,8 +2369,8 @@ If you have any wtfs, ideas or suggestions, please share. You can use these quick links for Twitter and Linkedin. -[Twitter](https://twitter.com/intent/tweet?url=https://github.com/satwikkansal/wtfpython&hastags=python,wtfpython) | -[Linkedin](https://www.linkedin.com/shareArticle?url=https://github.com/satwikkansal&title=What%20the%20f*ck%20Python!&summary=An%20interesting%20collection%20of%20subtle%20and%20tricky%20Python%20snippets.) +[Twitter](https://twitter.com/intent/tweet?url=https://github.com/satwikkansal/wtfpython&hastags=python,wtfpython) + | [Linkedin](https://www.linkedin.com/shareArticle?url=https://github.com/satwikkansal&title=What%20the%20f*ck%20Python!&summary=An%20interesting%20collection%20of%20subtle%20and%20tricky%20Python%20snippets.) ## Need a pdf version?