Utilities#

Various module utilities mostly used from tests.

Factory#

Imaging#

class lotus.utils.imaging.SampleImageCrafter(*args, **kwargs)[source]#

Craft a basic sample image, either a bitmap or a SVG.

Basically every supported format from PIL should work however this code only knows about JPEG, GIF, PNG and SVG.

Keyword Arguments:

font (Pil.ImageFont) – A font object to use. This is only used for bitmap image. It is strongly recommended to use a TrueType font. Default is None, this will use the default PIL font. Note than text without a TrueType font will be badly positionned (almost centered but largely shifted).

get_text_content(text, width, height)[source]#

Get the text content to include in image.

Parameters:

  • text (string or boolean) – Either a string to use it as content or True to make automatic content from given sizes such as 320x240 (for width value 320 and height value 240). If string is given it should be a short text else it is not guaranteed to fit. If you don’t want text content, just pass a empty string.

  • width (integer) – Width value to display in automatic text content.

  • height (integer) – Height value to display in automatic text content.

Returns:

Content to include in image.

Return type:

string

get_file_extension(format_name)[source]#

Get correct file extension depending format name.

Parameters:

format_name (string) – The format name to use to get the right file extension. It could be any format supported. JPEG and JPG will traduces to jpg file extension.

Returns:

File extension without leading dot.

Return type:

string

get_mode(format_name)[source]#

Get correct image color mode depending format name.

Parameters:

format_name (string) – The format name to use to get the right file extension. It could be any format supported. PNG will be a RGBA mode, every other format will be RGB.

Returns:

Image color mode name.

Return type:

string

get_filename(file_extension, filename=None, bg_color=None)[source]#

Get filename.

Parameters:

file_extension (string) – File extension to use in automatic filename. Can be anything if filename argument is given since it will be ignored.

Keyword Arguments:

  • filename (string) – Custom filename to use, every other arguments won’t be used to compute filename.

  • bg_color (string) – A color name to use in automatic filename. For real, this can be anything since it is not validated.

Returns:

File name.

Return type:

string

build(filename=None, size=(100, 100), bg_color='blue', text_color='white', text=None, format_name='PNG')[source]#

Build config for content creation

Keyword Arguments:

  • filename (string) – Custom file name (with file extension) to override the automatic file name (based on other given arguments). Default is None which will produce an automatic file name.

  • size (tuple) – A tuple of two integers respectively for width and height. Default to (100, 100) which will produce a square of 100 pixels.

  • bg_color (string) – Color name to use to paint image background. Default to blue.

  • text_color (string) – Color name to use to draw possible content text. Default to white.

  • text (string) – Custom content text to include in image. Default to None which will produce an automatic content based on size. Use an empty string to avoid content text in image.

  • format_name (string) – Image format name to use. Default to PNG.

Returns:

Configuration to use to create image file.

Return type:

dict

create_vectorial(width, height, bg_color, text_content=None, text_color=None)[source]#

Create SVG content.

Parameters:

  • width (integer) – Image width.

  • height (integer) – Image height.

  • bg_color (object) – Color name to paint image background.

Keyword Arguments:

  • text_content (string) – Content text to include instead of automatic content text.

  • text_color (string) – Color name to draw text instead of default one. It is required if you want to use the custom context text.

Returns:

SVG content in a string buffer.

Return type:

io.StringIO

create_bitmap(mode, format_name, width, height, bg_color, text_content=None, text_color=None)[source]#

Create Bitmap image object.

Parameters:

  • mode (string) – Image color mode to use.

  • format_name (string) – Image format name to use.

  • width (integer) – Image width.

  • height (integer) – Image height.

  • bg_color (object) – Color name to paint image background.

Keyword Arguments:

  • text_content (string) – Content text to include instead of automatic content text.

  • text_color (string) – Color name to draw text instead of default one. It is required if you want to use the custom context text.

Returns:

Image object in a byte buffer.

Return type:

io.BytesIO

create(filename=None, size=(100, 100), bg_color='blue', text_color='white', text=None, format_name='PNG')[source]#

Create an image inside a file object.

Return a File object with a dummy generated image on the fly by PIL or possibly a SVG file.

With default argument values the generated image will be a simple blue square in PNG with no text.

Optionally, you can have any other supported format (JPEG, GIF, SVG), a custom background color and a text.

Keyword Arguments:

  • filename (string) – Filename for created file, default to bg_color value joined to extension with format value in lowercase (or jpg if format is JPEG). Note than final filename may be different if all tests use the same one since Django will append a hash for uniqueness.

  • format_name (string) – Format name as available from PIL: JPEG, PNG or GIF. SVG format is also possible to create a dummy SVG file.

  • size (tuple) – A tuple of two integers respectively for width and height. Default to (100, 100) which will produce a square of 100 pixels.

  • bg_color (string) – Color value to fill image, this should be a valid value for PIL.ImageColor: https://pillow.readthedocs.io/en/stable/reference/ImageColor.html or a valid HTML color name for SVG format. Default to “blue”. WARNING: If you don’t use named color (like “white” or “yellow”), you should give a custom filename to filename argument else the filename may be weird (like #111111.png).

  • text_color (string) – Color value for text. This should be a valid value for PIL.ImageColor: https://pillow.readthedocs.io/en/stable/reference/ImageColor.html Default to “white”.

  • text (string or boolean) – True for automatic image size like 320x240 (for width value 320 and height value 240). None or False to disable text drawing (this is the default value). A string for custom text, this should be a short text else it is not guaranteed to fit.

Returns:

File object.

Return type:

object

class lotus.utils.imaging.DjangoSampleImageCrafter(*args, **kwargs)[source]#

Alike SampleImageCrafter but return a Django File instead of a file object.

create(*args, **kwargs)[source]#

Create an image inside a Django File object.

Parameters:

  • *args – The same positional arguments as from SampleImageCrafter.

  • **kwargs – The same keyword arguments as from SampleImageCrafter.

Returns:

File object.

Return type:

django.core.files.File

Tests#