Esc/Pos

Module escpos.escpos

Main class.

This module contains the abstract base class Escpos.

author:: python-escpos developers
organization:: Bashlinux and python-escpos
copyright:: Copyright (c) 2012-2017 Bashlinux and python-escpos
license:: MIT

class escpos.escpos.Escpos(profile=None, magic_encode_args=None, **kwargs)[source]

Bases: object

ESC/POS Printer object.

This class is the abstract base class for an Esc/Pos-printer. The printer implementations are children of this class.

property device: Literal[None] | object

Implements a self-open mechanism.

An attempt to get the property before open the connection will cause the connection to open.

open()[source]: Open a printer device/connection.

image(img_source, high_density_vertical=True, high_density_horizontal=True, impl='bitImageRaster', fragment_height=960, center=False)[source]

Print an image.

You can select whether the printer should print in high density or not. The default value is high density. When printing in low density, the image will be stretched.

Esc/Pos supplies several commands for printing. This function supports three of them. Please try to vary the implementations if you have any problems. For example the printer IT80-002 will have trouble aligning images that are not printed in Column-mode.

The available printing implementations are:

bitImageRaster: prints with the GS v 0-command

graphics: prints with the GS ( L-command

bitImageColumn: prints with the ESC *-command

When trying to center an image make sure you have initialized the printer with a valid profile, that contains a media width pixel field. Otherwise the centering will have no effect.

Parameters:

img_source – PIL image or filename to load: jpg, gif, png or bmp
high_density_vertical (bool) – print in high density in vertical direction default: True
high_density_horizontal (bool) – print in high density in horizontal direction default: True
impl (str) – choose image printing mode between bitImageRaster, graphics or bitImageColumn
fragment_height (int) – Images larger than this will be split into multiple fragments default: 960
center (bool) – Center image horizontally default: False

Return type:

None

qr(content, ec=0, size=3, model=2, native=False, center=False, impl='bitImageRaster')[source]

Print QR Code for the provided string.

Parameters:

content – The content of the code. Numeric data will be more efficiently compacted.
ec – Error-correction level to use. One of QR_ECLEVEL_L (default), QR_ECLEVEL_M, QR_ECLEVEL_Q or QR_ECLEVEL_H. Higher error correction results in a less compact code.
size – Pixel size to use. Must be 1-16 (default 3)
model – QR code model to use. Must be one of QR_MODEL_1, QR_MODEL_2 (default) or QR_MICRO (not supported by all printers).
native – True to render the code on the printer, False to render the code as an image and send it to the printer (Default)
center – Centers the code default: False
impl – Image-printing-implementation, refer to image() for details

Return type:

None

charcode(code='AUTO')[source]

Set Character Code Table.

Sets the control sequence from CHARCODE in escpos.constants as active. It will be sent with the next text sequence. If you set the variable code to AUTO it will try to automatically guess the right codepage. (This is the standard behavior.)

Parameters:: code (str) – Name of CharCode
Raises:: CharCodeError
Return type:: None

static check_barcode(bc, code)[source]

Check if barcode is OK.

This method checks if the barcode is in the proper format. The validation concerns the barcode length and the set of characters, but won’t compute/validate any checksum. The full set of requirement for each barcode type is available in the ESC/POS documentation.

As an example, using EAN13, the barcode 12345678901 will be correct, because it can be rendered by the printer. But it does not suit the EAN13 standard, because the checksum digit is missing. Adding a wrong checksum in the end will also be considered correct, but adding a letter won’t (EAN13 is numeric only).

Todo

Add a method to compute the checksum for the different standards

Todo

For fixed-length standards with mandatory checksum (EAN, UPC), compute and add the checksum automatically if missing.

Parameters:

bc (str) – barcode format, see barcode()
code (str) – alphanumeric data to be printed as bar code, see barcode()

Returns:

bool

barcode(code, bc, height=64, width=3, pos='BELOW', font='A', align_ct=True, function_type=None, check=True, force_software=False)[source]

Print barcode.

Automatic hardware|software barcode renderer according to the printer capabilities.

Defaults to hardware barcode and its format types if supported. Automatically switches to software barcode renderer if hardware does not support a barcode type that is supported by software. (e.g. JAN, ISSN, etc.).

Set force_software=True to force the software renderer according to the profile. Set force_software=graphics|bitImageColumn|bitImageRaster to specify a renderer.

Ignores caps, special chars and whitespaces in barcode type names. So “EAN13”, “ean-13”, “Ean_13”, “EAN 13” are all accepted.

Parameters:

code – alphanumeric data to be printed as bar code (payload).
bc – barcode format type (EAN13, CODE128, JAN, etc.).
height (int) – barcode module height (in printer dots), has to be between 1 and 255. default: 64
width (int) – barcode module width (in printer dots), has to be between 2 and 6. default: 3
pos (str) – text position (ABOVE, BELOW, BOTH, OFF) relative to the barcode (ignored in software renderer). default: BELOW
font (str) – select font A or B (ignored in software renderer). default: A
align_ct (bool) – If True, center the barcode. default: True
function_type – ESCPOS function type A or B. None to guess it from profile (ignored in software renderer). default: None
check (bool) – If True, checks that the code meets the requirements of the barcode type. default: True
force_software (Union[bool, str]) – If True, force the use of software barcode renderer from profile. If “graphics”, “bitImageColumn” or “bitImageRaster”, force the use of specific renderer.

Raises:

BarcodeCodeError, BarcodeTypeError

Return type:

None

Note

Get all supported formats at:

Hardware: BARCODE_FORMATS
Software: Python barcode documentation

text(txt)[source]

Print alpha-numeric text.

The text has to be encoded in the currently selected codepage. The input text has to be encoded in unicode.

Parameters:: txt – text to be printed
Raises:: TextError

textln(txt='')[source]

Print alpha-numeric text with a newline.

The text has to be encoded in the currently selected codepage. The input text has to be encoded in unicode.

Parameters:: txt – text to be printed with a newline
Raises:: TextError

ln(count=1)[source]

Print a newline or more.

Parameters:: count – number of newlines to print
Raises:: ValueError if count < 0

block_text(txt, font='0', columns=None)[source]

Print text wrapped to specific columns.

Text has to be encoded in unicode.

Parameters:

txt – text to be printed
font – font to be used, can be a or b
columns – amount of columns

Returns:

None

set(align=None, font=None, bold=None, underline=None, width=None, height=None, density=None, invert=None, smooth=None, flip=None, normal_textsize=None, double_width=None, double_height=None, custom_size=None)[source]

Set text properties by sending them to the printer.

If a value for a parameter is not supplied, nothing is sent for this type of format.

Parameters:

align (Optional[str]) –
horizontal position for text, possible values are:
- ’center’
- ’left’
- ’right’
font (Optional[str]) – font given as an index, a name, or one of the special values ‘a’ or ‘b’, referring to fonts 0 and 1.
bold (Optional[bool]) – text in bold
underline (Optional[int]) – underline mode for text, decimal range 0-2
normal_textsize (Optional[bool]) – switch to normal text size if True
double_height (Optional[bool]) – doubles the height of the text
double_width (Optional[bool]) – doubles the width of the text
custom_size (Optional[bool]) – uses custom size specified by width and height parameters. Cannot be used with double_width or double_height.
width (Optional[int]) – text width multiplier when custom_size is used, decimal range 1-8
height (Optional[int]) – text height multiplier when custom_size is used, decimal range 1-8
density (Optional[int]) – print density, value from 0-8, if something else is supplied the density remains unchanged
invert (Optional[bool]) – True enables white on black printing
smooth (Optional[bool]) – True enables text smoothing. Effective on 4x4 size text and larger
flip (Optional[bool]) – True enables upside-down printing

Return type:

None

set_with_default(align='left', font='a', bold=False, underline=0, width=1, height=1, density=9, invert=False, smooth=False, flip=False, double_width=False, double_height=False, custom_size=False)[source]

Set default text properties by sending them to the printer.

This function has the behavior of the set()-method from before version 3. If a parameter to this method is not supplied, a default value will be sent. Otherwise this method forwards the values to the escpos.Escpos.set().

Parameters:

align (Optional[str]) –
horizontal position for text, possible values are:
- ’center’
- ’left’
- ’right’
default: ‘left’
font (Optional[str]) – font given as an index, a name, or one of the special values ‘a’ or ‘b’, referring to fonts 0 and 1.
bold (Optional[bool]) – text in bold, default: False
underline (Optional[int]) – underline mode for text, decimal range 0-2, default: 0
double_height (Optional[bool]) – doubles the height of the text
double_width (Optional[bool]) – doubles the width of the text
custom_size (Optional[bool]) – uses custom size specified by width and height parameters. Cannot be used with double_width or double_height.
width (Optional[int]) – text width multiplier when custom_size is used, decimal range 1-8, default: 1
height (Optional[int]) – text height multiplier when custom_size is used, decimal range 1-8, default: 1
density (Optional[int]) – print density, value from 0-8, if something else is supplied the density remains unchanged
invert (Optional[bool]) – True enables white on black printing, default: False
smooth (Optional[bool]) – True enables text smoothing. Effective on 4x4 size text and larger, default: False
flip (Optional[bool]) – True enables upside-down printing, default: False

Return type:

None

line_spacing(spacing=None, divisor=180)[source]

Set line character spacing.

If no spacing is given, we reset it to the default.

There are different commands for setting the line spacing, using a different denominator:

‘+’’ line_spacing/360 of an inch, 0 <= line_spacing <= 255 ‘3’ line_spacing/180 of an inch, 0 <= line_spacing <= 255 ‘A’ line_spacing/60 of an inch, 0 <= line_spacing <= 85

Some printers may not support all of them. The most commonly available command (using a divisor of 180) is chosen.

Return type:: None

cut(mode='FULL', feed=True)[source]

Cut paper.

Without any arguments the paper will be cut completely. With ‘mode=PART’ a partial cut will be attempted. Note however, that not all models can do a partial cut. See the documentation of your printer for details.

Parameters:

mode (str) – set to ‘PART’ for a partial cut. default: ‘FULL’
feed (bool) – print and feed before cutting. default: true

Raises:

ValueError – if mode not in (‘FULL’, ‘PART’)

Return type:

None

cashdraw(pin)[source]

Send pulse to kick the cash drawer.

Kick cash drawer on pin 2 (CD_KICK_2) or pin 5 (CD_KICK_5) according to the default parameters. For non default parameters send a decimal sequence i.e. [27,112,48] or [27,112,0,25,255].

Parameters:: pin – pin number, 2 or 5 or list of decimals
Raises:: CashDrawerError
Return type:: None

linedisplay_select(select_display=False)[source]

Select the line display or the printer.

This method is used for line displays that are daisy-chained between your computer and printer. If you set select_display to true, only the display is selected and if you set it to false, only the printer is selected.

Parameters:: select_display (bool) – whether the display should be selected or the printer
Return type:: None

linedisplay_clear()[source]

Clear the line display and resets the .

This method is used for line displays that are daisy-chained between your computer and printer.

Return type:: None

linedisplay(text)[source]

Display text on a line display connected to your printer.

You should connect a line display to your printer. You can do this by daisy-chaining the display between your computer and printer.

Parameters:: text (str) – Text to display
Return type:: None

hw(hw)[source]

Hardware operations.

Parameters:

hw (str) –

hardware action, may be:

INIT
SELECT
RESET

Return type:

None

print_and_feed(n=1)[source]

Print data in print buffer and feed n lines.

If n not in range (0, 255) then a ValueError will be raised.

Parameters:: n (int) – number of n to feed. 0 <= n <= 255. default: 1
Raises:: ValueError – if not 0 <= n <= 255
Return type:: None

control(ctl, count=5, tab_size=8)[source]

Feed control sequences.

Parameters:

ctl (str) –
string for the following control sequences:
- LF for Line Feed
- FF for Form Feed
- CR for Carriage Return
- HT for Horizontal Tab
- VT for Vertical Tab
count (int) – integer between 1 and 32, controls the horizontal tab count. Defaults to 5.
tab_size (int) – integer between 1 and 255, controls the horizontal tab size in characters. Defaults to 8

Raises:

TabPosError

Return type:

None

panel_buttons(enable=True)[source]

Control the panel buttons on the printer (e.g. FEED).

When enable is set to False the panel buttons on the printer will be disabled. Calling the method with enable=True or without argument will enable the panel buttons.

If panel buttons are enabled, the function of the panel button, such as feeding, will be executed upon pressing the button. If the panel buttons are disabled, pressing them will not have any effect.

This command is effective until the printer is initialized, resetted or power-cycled. The default is enabled panel buttons.

Some panel buttons will always work, especially when the printer is opened. See for more information the manual of your printer and the escpos-command-reference.

Parameters:: enable (bool) – controls the panel buttons
Return type:: None

query_status(mode)[source]

Query the printer for its status.

Returns an array of integers containing it.

Parameters:: mode (bytes) – Integer that sets the status mode queried to the printer. - RT_STATUS_ONLINE: Printer status. - RT_STATUS_PAPER: Paper sensor.
Return type:: List[int]

is_online()[source]

Query the online status of the printer.

Return type:: bool
Returns:: When online, returns True; False otherwise.

paper_status()[source]

Query the paper status of the printer.

Returns 2 if there is plenty of paper, 1 if the paper has arrived to the near-end sensor and 0 if there is no paper.

Returns:: 2: Paper is adequate. 1: Paper ending. 0: No paper.

target(type='ROLL')[source]

Select where to print to.

Print to the thermal printer by default (ROLL) or print to the slip dot matrix printer if supported (SLIP)

Return type:: None

eject_slip()[source]

Eject the slip/cheque.

Return type:: None

print_and_eject_slip()[source]

Print and eject.

Prints data from the buffer to the slip station and if the paper sensor is covered, reverses the slip out the front of the printer far enough to be accessible to the operator. The impact station opens the platen in all cases.

Return type:: None

use_slip_only()[source]

Select the Slip Station for all functions.

The receipt station is the default setting after the printer is initialized or the Clear Printer (0x10) command is received

Return type:: None

buzzer(times=2, duration=4)[source]

Activate the internal printer buzzer on supported printers.

The ‘times’ parameter refers to the ‘n’ escpos command parameter, which means how many times the buzzer will be ‘beeped’.

Parameters:

times (int) – Integer between 1 and 9, indicates the buzzer beeps.
duration (int) – Integer between 1 and 9, indicates the beep duration.

Return type:

None

Returns:

None

class escpos.escpos.EscposIO(printer, autocut=True, autoclose=True, **kwargs)[source]

Bases: object

ESC/POS Printer IO object.

Allows the class to be used together with the with-statement. You have to define a printer instance and assign it to the EscposIO class. This example explains the usage:

with EscposIO(printer.Serial('/dev/ttyUSB0')) as p:
    p.set(font='a', height=2, align='center', text_type='bold')
    p.printer.set(align='left')
    p.printer.image('logo.gif')
    p.writelines('Big line\\n', font='b')
    p.writelines('Привет')
    p.writelines('BIG TEXT', width=2)

After the with-statement the printer automatically cuts the paper if autocut is True.

set(**kwargs)[source]

Set the printer-parameters.

Controls which parameters will be passed to Escpos.set(). For more information on the parameters see the set()-methods documentation. These parameters can also be passed with this class’ constructor or the writelines()-method.

Parameters:: kwargs – keyword-parameters that will be passed to Escpos.set()
Return type:: None

writelines(text, **kwargs)[source]: Print text.

close()[source]

Close printer.

Called upon closing the with-statement.