Tools

serial.tools.list_ports

This module can be executed to get a list of ports (python -m serial.tools.list_ports). It also contains the following functions.

serial.tools.list_ports.comports(include_links=False)
Parameters:include_links (bool) – include symlinks under /dev when they point to a serial port
Returns:a list containing ListPortInfo objects.

The function returns a list of ListPortInfo objects.

Items are returned in no particular order. It may make sense to sort the items. Also note that the reported strings are different across platforms and operating systems, even for the same device.

Note

Support is limited to a number of operating systems. On some systems description and hardware ID will not be available (None).

Under Linux, OSX and Windows, extended information will be available for USB devices (e.g. the ListPortInfo.hwid string contains VID:PID, SER (serial number), LOCATION (hierarchy), which makes them searchable via grep(). The USB info is also available as attributes of ListPortInfo.

If include_links is true, all devices under /dev are inspected and tested if they are a link to a known serial port device. These entries will include LINK in their hwid string. This implies that the same device listed twice, once under its original name and once under linked name.

Platform:Posix (/dev files)
Platform:Linux (/dev files, sysfs)
Platform:OSX (iokit)
Platform:Windows (setupapi, registry)
serial.tools.list_ports.grep(regexp, include_links=False)
Parameters:
  • regexp – regular expression (see stdlib re)
  • include_links (bool) – include symlinks under /dev when they point to a serial port
Returns:

an iterable that yields ListPortInfo objects, see also comports().

Search for ports using a regular expression. Port name, description and hwid are searched (case insensitive). The function returns an iterable that contains the same data that comports() generates, but includes only those entries that match the regexp.

class serial.tools.list_ports.ListPortInfo

This object holds information about a serial port. It supports indexed access for backwards compatibility, as in port, desc, hwid = info.

device

Full device name/path, e.g. /dev/ttyUSB0. This is also the information returned as first element when accessed by index.

name

Short device name, e.g. ttyUSB0.

description

Human readable description or n/a. This is also the information returned as second element when accessed by index.

hwid

Technical description or n/a. This is also the information returned as third element when accessed by index.

USB specific data, these are all None if it is not an USB device (or the platform does not support extended info).

vid

USB Vendor ID (integer, 0...65535).

pid

USB product ID (integer, 0...65535).

serial_number

USB serial number as a string.

location

USB device location string (“<bus>-<port>[-<port>]...”)

manufacturer

USB manufacturer string, as reported by device.

product

USB product string, as reported by device.

interface

Interface specific description, e.g. used in compound USB devices.

Comparison operators are implemented such that the ListPortInfo objects can be sorted by device. Strings are split into groups of numbers and text so that the order is “natural” (i.e. com1 < com2 < com10).

Command line usage

Help for python -m serial.tools.list_ports:

usage: list_ports.py [-h] [-v] [-q] [-n N] [-s] [regexp]

Serial port enumeration

positional arguments:
  regexp               only show ports that match this regex

optional arguments:
  -h, --help           show this help message and exit
  -v, --verbose        show more messages
  -q, --quiet          suppress all messages
  -n N                 only output the N-th entry
  -s, --include-links  include entries that are symlinks to real devices

Examples:

  • List all ports with details:

    $ python -m serial.tools.list_ports -v
    /dev/ttyS0
        desc: ttyS0
        hwid: PNP0501
    /dev/ttyUSB0
        desc: CP2102 USB to UART Bridge Controller
        hwid: USB VID:PID=10C4:EA60 SER=0001 LOCATION=2-1.6
    2 ports found
    
  • List the 2nd port matching a USB VID:PID pattern:

    $ python -m serial.tools.list_ports 1234:5678 -q -n 2
    /dev/ttyUSB1
    

New in version 2.6.

Changed in version 3.0: returning ListPortInfo objects instead of a tuple

serial.tools.miniterm

This is a console application that provides a small terminal application.

Miniterm itself does not implement any terminal features such as VT102 compatibility. However it may inherit these features from the terminal it is run. For example on GNU/Linux running from an xterm it will support the escape sequences of the xterm. On Windows the typical console window is dumb and does not support any escapes. When ANSI.sys is loaded it supports some escapes.

The default is to filter terminal control characters, see --filter for different options.

Miniterm:

--- Miniterm on /dev/ttyS0: 9600,8,N,1 ---
--- Quit: Ctrl+]  |  Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---

Command line options can be given so that binary data including escapes for terminals are escaped or output as hex.

Miniterm supports RFC 2217 remote serial ports and raw sockets using URL Handlers such as rfc2217://<host>:<port> respectively socket://<host>:<port> as port argument when invoking.

Command line options python -m serial.tools.miniterm -h:

usage: miniterm.py [-h] [--parity {N,E,O,S,M}] [--rtscts] [--xonxoff]
                   [--rts RTS] [--dtr DTR] [-e] [--encoding CODEC] [-f NAME]
                   [--eol {CR,LF,CRLF}] [--raw] [--exit-char NUM]
                   [--menu-char NUM] [-q] [--develop]
                   [port] [baudrate]

Miniterm - A simple terminal program for the serial port.

positional arguments:
  port                  serial port name
  baudrate              set baud rate, default: 9600

optional arguments:
  -h, --help            show this help message and exit

port settings:
  --parity {N,E,O,S,M}  set parity, one of {N E O S M}, default: N
  --rtscts              enable RTS/CTS flow control (default off)
  --xonxoff             enable software flow control (default off)
  --rts RTS             set initial RTS line state (possible values: 0, 1)
  --dtr DTR             set initial DTR line state (possible values: 0, 1)
  --ask                 ask again for port when open fails

data handling:
  -e, --echo            enable local echo (default off)
  --encoding CODEC      set the encoding for the serial port (e.g. hexlify,
                        Latin1, UTF-8), default: UTF-8
  -f NAME, --filter NAME
                        add text transformation
  --eol {CR,LF,CRLF}    end of line mode
  --raw                 Do no apply any encodings/transformations

hotkeys:
  --exit-char NUM       Unicode of special character that is used to exit the
                        application, default: 29
  --menu-char NUM       Unicode code of special character that is used to
                        control miniterm (menu), default: 20

diagnostics:
  -q, --quiet           suppress non-error messages
  --develop             show Python traceback on error

Available filters (--filter option):

  • colorize: Apply different colors for received and echo
  • debug: Print what is sent and received
  • default: remove typical terminal control codes from input
  • direct: do-nothing: forward all data unchanged
  • nocontrol: Remove all control codes, incl. CR+LF
  • printable: Show decimal code for all non-ASCII characters and replace most control codes

Miniterm supports some control functions while being connected. Typing Ctrl+T Ctrl+H when it is running shows the help text:

--- pySerial (3.0a) - miniterm - help
---
--- Ctrl+]   Exit program
--- Ctrl+T   Menu escape key, followed by:
--- Menu keys:
---    Ctrl+T  Send the menu character itself to remote
---    Ctrl+]  Send the exit character itself to remote
---    Ctrl+I  Show info
---    Ctrl+U  Upload file (prompt will be shown)
---    Ctrl+A  encoding
---    Ctrl+F  edit filters
--- Toggles:
---    Ctrl+R  RTS   Ctrl+D  DTR   Ctrl+B  BREAK
---    Ctrl+E  echo  Ctrl+L  EOL
---
--- Port settings (Ctrl+T followed by the following):
---    p          change port
---    7 8        set data bits
---    N E O S M  change parity (None, Even, Odd, Space, Mark)
---    1 2 3      set stop bits (1, 2, 1.5)
---    b          change baud rate
---    x X        disable/enable software flow control
---    r R        disable/enable hardware flow control

Ctrl+T s suspends the connection (port is opened) and reconnects when a key is pressed. This can be used to temporarily access the serial port with an other application, without exiting miniterm. If reconnecting fails it is also possible to exit (Ctrl+]) or change the port (p).

Changed in version 2.5: Added Ctrl+T menu and added support for opening URLs.

Changed in version 2.6: File moved from the examples to serial.tools.miniterm.

Changed in version 3.0: Apply encoding on serial port, convert to Unicode for console. Added new filters, default to stripping terminal control sequences. Added --ask option.