## Motivation { #motivation }

Commençons par un exemple simple :

{* ../../docs_src/python_types/tutorial001_py310.py *}

Exécuter ce programme affiche :

```
John Doe
```

La fonction fait ce qui suit :

* Prend un `first_name` et un `last_name`.
* Convertit la première lettre de chacun en majuscule avec `title()`.

Ensuite, vers la fin du `Dockerfile`, nous copions tout le code. Comme c'est ce qui **change le plus fréquemment**, nous le plaçons vers la fin, car presque toujours, tout ce qui suit cette étape ne pourra pas utiliser le cache.

```Dockerfile
COPY ./app /code/app
```

### Construire l'image Docker { #build-the-docker-image }

pkg net/smtp, method (*Client) Data() (io.WriteCloser, error)
pkg net/smtp, method (*Client) Extension(string) (bool, string)
pkg net/smtp, method (*Client) Mail(string) error
pkg net/smtp, method (*Client) Quit() error
pkg net/smtp, method (*Client) Rcpt(string) error
pkg net/smtp, method (*Client) Reset() error
pkg net/smtp, method (*Client) StartTLS(*tls.Config) error
pkg net/smtp, method (*Client) Verify(string) error

  This speech caused a remarkable sensation among the party.
Some of the birds hurried off at once:  one old Magpie began
wrapping itself up very carefully, remarking, `I really must be
getting home; the night-air doesn't suit my throat!' and a Canary
called out in a trembling voice to its children, `Come away, my
dears!  It's high time you were all in bed!'  On various pretexts
they all moved off, and Alice was soon left alone.

  This speech caused a remarkable sensation among the party.
Some of the birds hurried off at once:  one old Magpie began
wrapping itself up very carefully, remarking, `I really must be
getting home; the night-air doesn't suit my throat!' and a Canary
called out in a trembling voice to its children, `Come away, my
dears!  It's high time you were all in bed!'  On various pretexts
they all moved off, and Alice was soon left alone.

"die", "in", "een", "hij", "het", "niet", "zijn", "is", "was", "op", "aan", "met", "als", "voor", "had", "er", "maar", "om", "hem", "dan", "zou", "of", "wat", "mijn", "men", "dit", "zo", "door", "over", "ze", "zich", "bij", "ook", "tot", "je", "mij", "uit", "der", "daar", "haar", "naar", "heb", "hoe", "heeft", "hebben", "deze", "u", "want", "nog", "zal", "me", "zij", "nu", "ge", "geen", "omdat", "iets", "worden", "toch", "al", "waren", "veel", "meer", "doen", "toen", "moet", "ben", "zonder", "kan", "hun",...

"die", "in", "een", "hij", "het", "niet", "zijn", "is", "was", "op", "aan", "met", "als", "voor", "had", "er", "maar", "om", "hem", "dan", "zou", "of", "wat", "mijn", "men", "dit", "zo", "door", "over", "ze", "zich", "bij", "ook", "tot", "je", "mij", "uit", "der", "daar", "haar", "naar", "heb", "hoe", "heeft", "hebben", "deze", "u", "want", "nog", "zal", "me", "zij", "nu", "ge", "geen", "omdat", "iets", "worden", "toch", "al", "waren", "veel", "meer", "doen", "toen", "moet", "ben", "zonder", "kan", "hun",...

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display: $value !important; }\n    }\n  }\n}\n\n\n//\n// Utilities for toggling `display` in print\n//\n\n@media print {\n  @each $value in $displays {\n    .d-print-#{$value} { display: $value !important; }\n  }\n}\n","// Credit: Nicolas Gallagher and SUIT CSS.\n\n.embed-responsive {\n  position: relative;\n  display: block;\n  width: 100%;\n  padding: 0;\n  overflow: hidden;\n\n  &::before {\n    display: block;\n    content: \"\";\n  }\n\n  .embed-responsive-item,\n  iframe,\n  embed,\n  object,\n...