There are two ways to create sets: using curly braces`{}` and thebult-in function`set()`

There are two ways to create sets: using curly braces`{}` and thebuilt-in function`set()`

>>> s= {1,2,3}

The_itertools_ module is acolection of toolsintented to be fast and use memory efficiently when handling iterators (like[lists](#lists) or[dictionaries](#dictionaries-and-structuring-data)).

The_itertools_ module is acollection of toolsintended to be fast and use memory efficiently when handling iterators (like[lists](#lists) or[dictionaries](#dictionaries-and-structuring-data)).

From the official[Python 3.x documentation](https://docs.python.org/3/library/itertools.html):

| Symbol| Matches|

|`?`| zeroor one of the preceding group.|

|`*`| zeroor more of the preceding group.|

|`+`| oneor more of the preceding group.|

|`{n}`| exactly n of the preceding group.|

|`{n,}`| nor more of the preceding group.|

|`{,m}`|0 to m of the preceding group.|

|`{n,m}`| at least nand at most m of the preceding p.|

|`{n,m}?`or`*?`or`+?`| performs a nongreedy match of the preceding p.|

|`^spam`| means the string must beginwith spam.|

|`spam$`| means the string must endwith spam.|

|`.`|any character,except newline characters.|

| `\D`, `\W`, and `\S` | anything except a digit, word, or space acter, respectively. |

|`[abc]`|any character between the brackets (suchas a, b, ).|

|`[^abc]`|any character that isn’t between the brackets.|

| Symbol| Matches|

|`?`| zeroor one of the preceding group.|

|`*`| zeroor more of the preceding group.|

|`+`| oneor more of the preceding group.|

|`{n}`| exactly n of the preceding group.|

|`{n,}`| nor more of the preceding group.|

|`{,m}`|0 to m of the preceding group.|

|`{n,m}`| at least nand at most m of the preceding p.|

|`{n,m}?`or`*?`or`+?`| performs a nongreedy match of the preceding p.|

|`^spam`| means the string must beginwith spam.|

|`spam$`| means the string must endwith spam.|

|`.`|any character,except newline characters.|

| `\D`, `\W`, and `\S` | anything except a digit, word, or space, respectively. |

|`[abc]`|any character between the brackets (suchas a, b, ).|

|`[^abc]`|any character that isn’t between the brackets.|

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Compared toJSON,YAML allowsfor much better human maintainabilityand gives you the option to add comments.

Itis aconvinient choicefor configuration files where humans will have to edit it.

Itis aconvenient choicefor configuration files where humans will have to edit it.

There are two mainlibrairies allowing to access toYAML files:

There are two mainlibraries allowing to access toYAML files:

- [PyYaml](https://pypi.python.org/pypi/PyYAML)

- [Ruamel.yaml](https://pypi.python.org/pypi/ruamel.yaml)

[Anyconfig](https://pypi.python.org/pypi/anyconfig)is a very handy package allowing to abstractcompletly the underlying configurationfileformat. It allows to load a Python dictionaryfromJSON,YAML,TOML,and so on.

[Anyconfig](https://pypi.python.org/pypi/anyconfig)is a very handy package allowing to abstractcompletely the underlying configurationfileformat. It allows to load a Python dictionaryfromJSON,YAML,TOML,and so on.

Install itwith:

Exception: Thisis the error message.

Often it’s the code that calls the function,not the function itself, that knows how to handle anexpection. So you will commonly see araise statement inside a functionand thetryandexcept statementsin the code calling the function.

Often it’s the code that calls the function,not the function itself, that knows how to handle anexception. So you will commonly see araise statement inside a functionand thetryandexcept statementsin the code calling the function.

def box_print(symbol, width, height):