Welcome to easyticket_qrgen’s documentation!¶

Provides methods to create tickets from a template and create QR codes for them.

Here’s a short example on how to generate a ticket token and the qr code for it.

Example

>>> token = create_ticket_token()
>>> qr = create_qr(token)

See the method documentation for more parameters.

After a qr code is generated you can place it on a template image. In the following example the image template is assumed to be in the file “~/Pictures/ticket_template.png” and the QR code is placed on position (95, 109).

Example

>>> # load image
>>> template_img = Image.open('~/Pictures/ticket_template.png')
>>> # create a template object
>>> ticket_template = TicketTemplate(template_img)
>>> # need to call only once: always place qr code on that position
>>> ticket_template.add_qr_code((95, 109))
>>> # render qr code to PIL image
>>> content = render_pil(qr)
>>> # place this qr code on the ticket
>>> ticket = ticket_template.render({'qr_code': content})
>>> # the same template can be used to render more codes on the ticket
>>> ticket.show()

class easyticket_qrgen.qr_ticketgen.ImagePlaceable(corner, scale_to=None)[source]¶

An implementation of Placeable that pastes another image into the template.

In this case the content argument of place must be a PIL.Image.Image.

corner¶

The point on which the other image is placed in the template in the form (x, y).

Type:	two element tuple of ints

scale_to¶

If given the image pasted onto the template gets scaled to this dimension (width, height), otherwise the image is not scaled.

Type:	two element tuple of ints or None

place(image, content)[source]¶

Place something on the template image.

The type of content depends on the implementation, this can be another image or a text.

Parameters:	image (PIL.Image.Image) – The ticket template to be filled with content. content – The type depends on the implementation, could be a string or another image.
Returns:	Changes the image in-place.
Return type:	None

class easyticket_qrgen.qr_ticketgen.Placeable[source]¶

An abstract base class for all objects that add something to a template image.

Each implementation places something on the template image, another image or text with its place method.

place(image, content)[source]¶

Place something on the template image.

The type of content depends on the implementation, this can be another image or a text.

Parameters:	image (PIL.Image.Image) – The ticket template to be filled with content. content – The type depends on the implementation, could be a string or another image.
Returns:	Changes the image in-place.
Return type:	None

class easyticket_qrgen.qr_ticketgen.TicketTemplate(img, placables=None)[source]¶

Class that represents a ticket template.

It consists of a template image that is filled with content by Placeable objects.

Attributes:

img (PIL.Image.Image): The ticket template as a PIL image. placables (dict string to Placeable): Maps names for placables to a concrete Placable implementation.

add_qr_code(corner, scale_to=None)[source]¶

Add an entry to the placables dictionary with name ‘qr_code’ that places a generated qr code to the template.

It simply creates an ImagePlaceable with the specified arguments.

Parameters:	corner (two element tuple of ints) – The point on which the QR code is placed in the template in the form (x, y).

scale_to (two element tuple of ints or None): If given the QR code pasted onto the template gets scaled to: this dimension (width, height), otherwise the image is not scaled. The QR code should not be scaled but should be created with the right size before.

render(contents)[source]¶

Applies all placables on the given template image.

contents is a dictionary mapping the names from placables to the actual content. For example the placable added by add_qr_code has the name ‘qr_code’ and thus in content there should be an entry ‘qr_code’ mapping to a PIL image of the QR code.

Only the placables with a key in contents will be activated.

Parameters:	contents (dict) – Mapping the names from placables to the actual content.
Returns:	The template when all objects in placables haven been applied (creates a copy)s.
Return type:	PIL.Image.Image

easyticket_qrgen.qr_ticketgen.compute_qr_size(qr, scale, quiet_zone)[source]¶

Compute the size of the QR code when rendered to a PIL image in pixels.

Because QR codes are squares this is the width and height of the image.

Parameters:	qr (pyqrcode.QRCode) – The QR code to compute the size of. scale (int) – The size in pixels of on module of the QR code (one block in the code). quiet_zone (int) – The size of blocks left blank in the generated image, that is quiet_zone=4 leaves 4*scale free space on each side of the image.
Returns:	The size of the generated image in pixels.
Return type:	int

easyticket_qrgen.qr_ticketgen.create_qr(token, error='M', **kwargs)[source]¶

Generates a QR code for a given token.

The token can be generated with create_ticket_token, a QR code instance from pyqrcode is returned.

Parameters:	token (str) – The token to encode in the QR code. error (str) – The error level of the QR code (‘L’, ‘M’, ‘Q’, ‘H’), ‘L’ allowst the least number of errors, ‘H’ the most. *kwargs (dict*) – All additional arguments passed to pyqrcode.create.
Returns:	The QR code of the token.
Return type:	pyqrcode.QRCode

easyticket_qrgen.qr_ticketgen.create_ticket_token(length=64, mode='alphanumeric')[source]¶

Creates a token for a ticket.

The output is a cryptographically strong random sequence.

Parameters:	length (int) – The length of the token (number of characters). mode (str) – Either ‘int’ for a sequence of integer values or ‘alphanumeric’ for valid QR code chars.
Returns:	The string representation of the generated token with the given length.
Return type:	str

easyticket_qrgen.qr_ticketgen.render_pil(qr, module_color='black', bg='white', scale=4, quiet_zone=4)[source]¶

Render a QR code as a PIL image.

The qr code can obtained with create_qr, this QR code is then rendered to a new PIL image.

Parameters:	qr (pyqrcode.QRCode) – The QR code to render. module_color (PIL color) – The color to use for the modules (‘blocks’) in the QR code. bg (PIL color) – The background color of the QR code. scale (int) – The size in pixels of on module of the QR code (one block in the code). quiet_zone (int) – The size of blocks left blank in the generated image, that is quiet_zone=4 leaves 4*scale free space on each side of the image.
Returns:	The QR code rendered to a PIL image.
Return type:	PIL.Image.Image

easyticket_qrgen.qr_ticketgen.secret_sequence(num, sequence)[source]¶

Creates a random sequence (cryptographically strong random sequence).

Randomly chooses num elements from sequence and returns the random sequence as a string.

Parameters:	num (int) – The length of the output sequence. sequence (str) – The elements to choose from as a string, each char one possible option.
Returns:	The random sequence as a string (num random elements from sequence combined).
Return type:	str

Welcome to easyticket_qrgen’s documentation!¶

Indices and tables¶