scapy.utils

General utility functions.

scapy.utils.AutoArgparse(func: DecoratorCallable) None[source]

Generate an Argparse call from a function, then call this function.

Notes:

  • for the arguments to have a description, the sphinx docstring format must be used. See https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html

  • the arguments must be typed in Python (we ignore Sphinx-specific types) untyped arguments are ignored.

  • only types that would be supported by argparse are supported. The others are omitted.

class scapy.utils.CLIUtil[source]

Bases: object

Provides a Util class to easily create simple CLI tools in Scapy, that can still be used as an API.

Doc:
  • override the ps1() function

  • register commands with the @CLIUtil.addcomment decorator

  • call the loop() function when ready

classmethod addcommand(spaces: bool = False, globsupport: bool = False) Callable[[DecoratorCallable], DecoratorCallable][source]

Decorator to register a command

classmethod addcomplete(cmd: DecoratorCallable) Callable[[DecoratorCallable], DecoratorCallable][source]

Decorator to register a command completor

classmethod addoutput(cmd: DecoratorCallable) Callable[[DecoratorCallable], DecoratorCallable][source]

Decorator to register a command output processor

close() None[source]

Function called on exiting

commands: Dict[str, Callable[[...], Any]] = {'cat': <function smbclient.cat>, 'cd': <function smbclient.cd>, 'get': <function smbclient.get>, 'lcd': <function smbclient.lcd>, 'lls': <function smbclient.lls>, 'ls': <function smbclient.ls>, 'put': <function smbclient.put>, 'rm': <function smbclient.rm>, 'shares': <function smbclient.shares>, 'use': <function smbclient.use>}
commands_complete: Dict[str, Callable[[...], List[str]]] = {'cat': <function smbclient.cat_complete>, 'cd': <function smbclient.cd_complete>, 'get': <function smbclient.get_complete>, 'lcd': <function smbclient.lcd_complete>, 'ls': <function smbclient.ls_complete>, 'rm': <function smbclient.rm_complete>}
commands_output: Dict[str, Callable[[...], str]] = {'cat': <function smbclient.cat_output>, 'cd': <function smbclient.cd_output>, 'get': <function smbclient.get_output>, 'lcd': <function smbclient.lcd_output>, 'lls': <function smbclient.lls_output>, 'ls': <function smbclient.ls_output>, 'shares': <function smbclient.shares_output>}
help(cmd: str | None = None) None[source]

Return the help related to this CLI util

loop(debug: int = 0) None[source]

Main command handling loop

ps1() str[source]

Return the PS1 of the shell

class scapy.utils.ContextManagerCaptureOutput[source]

Bases: object

Context manager that intercept the console’s output.

Example: >>> with ContextManagerCaptureOutput() as cmco: … print(“hey”) … assert cmco.get_output() == “hey”

get_output(eval_bytes: bool = False) str[source]
class scapy.utils.ContextManagerSubprocess(prog: str, suppress: bool = True)[source]

Bases: object

Context manager that eases checking for unknown command, without crashing.

Example: >>> with ContextManagerSubprocess(“tcpdump”): >>> subprocess.Popen([“tcpdump”, “–version”]) ERROR: Could not execute tcpdump, is it installed?

class scapy.utils.EDecimal(value='0', context=None)[source]

Bases: Decimal

Extended Decimal

This implements arithmetic and comparison with float for backward compatibility

normalize(precision: int) EDecimal[source]
class scapy.utils.ERFEthernetReader(filename: IO[bytes] | str)[source]

Bases: PcapReader

read_packet(size: int = 65535, **kwargs: Any) Packet[source]
class scapy.utils.ERFEthernetReader_metaclass(name: Any, bases: str, dct: Any)[source]

Bases: PcapReader_metaclass

static open(fname) Tuple[str, IO[bytes] | GzipFile][source]

Open (if necessary) filename

class scapy.utils.ERFEthernetWriter(filename: IO[bytes] | str, gz: bool = False, append: bool = False, sync: bool = False)[source]

Bases: PcapWriter

A stream ERF Ethernet writer with more control than wrerf()

close() Any | None[source]
write(pkt: _PacketIterable) None[source]

Writes a Packet, a SndRcvList object, or bytes to a ERF file.

Parameters:

pkt (iterable[scapy.packet.Packet], scapy.packet.Packet) – Packet(s) to write (one record for each Packet)

write_packet(pkt: Packet) None[source]
class scapy.utils.EnumElement(key: str, value: int)[source]

Bases: object

class scapy.utils.Enum_metaclass(name: Any, bases: str, dct: Any)[source]

Bases: type

element_class[source]

alias of EnumElement

get(attr: str, val: Any | None = None) Any[source]
class scapy.utils.GenericPcapWriter[source]

Bases: object

linktype: int | None = None
nano = False
write_header(pkt: Packet | bytes | None) None[source]
write_packet(packet: bytes | Packet, sec: float | None = None, usec: int | None = None, caplen: int | None = None, wirelen: int | None = None) None[source]

Writes a single packet to the pcap file.

Parameters:
  • packet (scapy.packet.Packet or bytes) – Packet, or bytes for a single packet

  • sec (float) – time the packet was captured, in seconds since epoch. If not supplied, defaults to now.

  • usec (int or long) – If nano=True, then number of nanoseconds after the second that the packet was captured. If nano=False, then the number of microseconds after the second the packet was captured. If sec is not specified, this value is ignored.

  • caplen (int) – The length of the packet in the capture file. If not specified, uses len(raw(packet)).

  • wirelen (int) – The length of the packet on the wire. If not specified, tries packet.wirelen, otherwise uses caplen.

Returns:

None

Return type:

None

class scapy.utils.GenericRawPcapWriter[source]

Bases: GenericPcapWriter

close() Any | None[source]
f: IO[bytes] | GzipFile = None
fileno() int[source]
flush() Any | None[source]
header_present = False
nano = False
sync = False
write(pkt: _PacketIterable | bytes) None[source]

Writes a Packet, a SndRcvList object, or bytes to a pcap file.

Parameters:

pkt (iterable[scapy.packet.Packet], scapy.packet.Packet or bytes) – Packet(s) to write (one record for each Packet), or raw bytes to write (as one record).

class scapy.utils.PcapNgReader(filename: IO[bytes] | str)[source]

Bases: RawPcapNgReader, PcapReader

alternative[source]

alias of PcapReader

read_packet(size: int = 65535, **kwargs: Any) Packet[source]
recv(size: int = 65535, **kwargs: Any) Packet[source]
class scapy.utils.PcapNgWriter(filename: str)[source]

Bases: RawPcapNgWriter

A stream pcapng writer with more control than wrpcapng()

class scapy.utils.PcapReader(filename: IO[bytes] | str)[source]

Bases: RawPcapReader

alternative[source]

alias of PcapNgReader

read_all(count: int = -1) PacketList[source]
read_packet(size: int = 65535, **kwargs: Any) Packet[source]
recv(size: int = 65535, **kwargs: Any) Packet[source]
class scapy.utils.PcapReader_metaclass(name: Any, bases: str, dct: Any)[source]

Bases: type

Metaclass for (Raw)Pcap(Ng)Readers

static open(fname: IO[bytes] | str) Tuple[str, IO[bytes] | GzipFile, bytes][source]

Open (if necessary) filename, and read the magic.

class scapy.utils.PcapWriter(filename: IO[bytes] | str, linktype: int | None = None, gz: bool = False, endianness: str = '', append: bool = False, sync: bool = False, nano: bool = False, snaplen: int = 65535, bufsz: int = 4096)[source]

Bases: RawPcapWriter

A stream PCAP writer with more control than wrpcap()

class scapy.utils.PeriodicSenderThread(sock: Any, pkt: _PacketIterable, interval: float = 0.5, ignore_exceptions: bool = True)[source]

Bases: Thread

run() None[source]
stop() None[source]
class scapy.utils.RawPcapNgReader(filename: IO[bytes] | str)[source]

Bases: RawPcapReader

A stateful pcapng reader. Each packet is returned as bytes.

PacketMetadata[source]

alias of PacketMetadataNg

alternative[source]

alias of RawPcapReader

class scapy.utils.RawPcapNgWriter(filename: str)[source]

Bases: GenericRawPcapWriter

A stream pcapng writer with more control than wrpcapng()

build_block(block_type: bytes, block_body: bytes, options: bytes | None = None) bytes[source]
class scapy.utils.RawPcapReader(filename: IO[bytes] | str)[source]

Bases: object

A stateful pcap reader. Each packet is returned as a string

class PacketMetadata(sec, usec, wirelen, caplen)[source]

Bases: tuple

caplen

Alias for field number 3

sec

Alias for field number 0

usec

Alias for field number 1

wirelen

Alias for field number 2

alternative[source]

alias of RawPcapNgReader

close() Any | None[source]
dispatch(callback: Callable[[Tuple[bytes, PacketMetadata]], Any]) None[source]

call the specified callback routine for each packet read

This is just a convenience function for the main loop that allows for easy launching of packet processing in a thread.

fileno() int[source]
nonblocking_socket = True
read_packet(size: int = 65535) Packet[source]
recv(size: int = 65535) bytes[source]

Emulate a socket

static select(sockets: List[SuperSocket], remain: float | None = None) List[SuperSocket][source]
class scapy.utils.RawPcapWriter(filename: IO[bytes] | str, linktype: int | None = None, gz: bool = False, endianness: str = '', append: bool = False, sync: bool = False, nano: bool = False, snaplen: int = 65535, bufsz: int = 4096)[source]

Bases: GenericRawPcapWriter

A stream PCAP writer with more control than wrpcap()

class scapy.utils.SingleConversationSocket(o: Any)[source]

Bases: object

send(x: Packet) Any[source]
sr(*args: Any, **kargs: Any) Any[source]
sr1(*args: Any, **kargs: Any) Any[source]
scapy.utils.atol(x: str) int[source]
scapy.utils.binrepr(val: int) str[source]
scapy.utils.checksum(pkt: bytes) int[source]
scapy.utils.checksum_endian_transform(chk)[source]
scapy.utils.chexdump(p: Packet | AnyStr, dump: bool = False) str | None[source]

Build a per byte hexadecimal representation

Example

>>> chexdump(IP())
0x45, 0x00, 0x00, 0x14, 0x00, 0x01, 0x00, 0x00, 0x40, 0x00, 0x7c, 0xe7, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00, 0x01  # noqa: E501
Parameters:
  • p – a Packet

  • dump – print the view if False

Returns:

a String only if dump=True

scapy.utils.colgen(*lstcol: Any, **kargs: Any) Iterator[Any][source]

Returns a generator that mixes provided quantities forever trans: a function to convert the three arguments into a color. lambda x,y,z:(x,y,z) by default

scapy.utils.corrupt_bits(data: str, p: float = 0.01, n: int | None = None) bytes[source]

Flip a given percentage (at least one bit) or number of bits from a string

scapy.utils.corrupt_bytes(data: str, p: float = 0.01, n: int | None = None) bytes[source]

Corrupt a given percentage (at least one byte) or number of bytes from a string

scapy.utils.decode_locale_str(x: bytes) str[source]

Decode bytes into a string using the system locale. Useful on Windows where it can be unusual (e.g. cp1252)

scapy.utils.do_graph(graph: str, prog: str | None = None, format: str | None = None, target: IO[bytes] | str | None = None, type: str | None = None, string: bool | None = None, options: List[str] | None = None) str | None[source]

Processes graph description using an external software. This method is used to convert a graphviz format to an image.

Parameters:
  • graph – GraphViz graph description

  • prog – which graphviz program to use

  • format – output type (svg, ps, gif, jpg, etc.), passed to dot’s “-T” option

  • string – if not None, simply return the graph string

  • target – filename or redirect. Defaults pipe to Imagemagick’s display program

  • options – options to be passed to prog

scapy.utils.export_object(obj: Any) None[source]
scapy.utils.fletcher16_checkbytes(binbuf: bytes, offset: int) bytes[source]

Calculates the Fletcher-16 checkbytes returned as 2 byte binary-string.

Including the bytes into the buffer (at the position marked by offset) the # noqa: E501 global Fletcher-16 checksum of the buffer will be 0. Thus it is easy to verify # noqa: E501 the integrity of the buffer on the receiver side.

For details on the algorithm, see RFC 2328 chapter 12.1.7 and RFC 905 Annex B. # noqa: E501

scapy.utils.fletcher16_checksum(binbuf: bytes) int[source]

Calculates Fletcher-16 checksum of the given buffer.

Note: If the buffer contains the two checkbytes derived from the Fletcher-16 checksum # noqa: E501 the result of this function has to be 0. Otherwise the buffer has been corrupted. # noqa: E501

scapy.utils.get_temp_dir(keep: bool = False) str[source]

Creates a temporary file, and returns its name.

Parameters:

keep – If False (default), the directory will be recursively deleted when Scapy exits.

Returns:

A full path to a temporary directory.

scapy.utils.get_temp_file(keep, autoext, fd)[source]
scapy.utils.get_temp_file(keep=False, autoext='', fd=False)

Creates a temporary file.

Parameters:
  • keep – If False, automatically delete the file when Scapy exits.

  • autoext – Suffix to add to the generated file name.

  • fd – If True, this returns a file-like object with the temporary file opened. If False (default), this returns a file path.

scapy.utils.get_terminal_width() int | None[source]

Get terminal width (number of characters) if in a window.

Notice: this will try several methods in order to support as many terminals and OS as possible.

scapy.utils.hexdiff(a: Packet | AnyStr, b: Packet | AnyStr, algo: str | None = None, autojunk: bool = False) None[source]

Show differences between 2 binary strings, Packets…

Available algorithms:
  • wagnerfischer: Use the Wagner and Fischer algorithm to compute the Levenstein distance between the strings then backtrack.

  • difflib: Use the difflib.SequenceMatcher implementation. This based on a modified version of the Ratcliff and Obershelp algorithm. This is much faster, but far less accurate. https://docs.python.org/3.8/library/difflib.html#difflib.SequenceMatcher

Parameters:
  • a

  • b – The binary strings, packets… to compare

  • algo – Force the algo to be ‘wagnerfischer’ or ‘difflib’. By default, this is chosen depending on the complexity, optimistically preferring wagnerfischer unless really necessary.

  • autojunk – (difflib only) See difflib documentation.

scapy.utils.hexdump(p: Packet | AnyStr, dump: bool = False) str | None[source]

Build a tcpdump like hexadecimal view

Parameters:
  • p – a Packet

  • dump – define if the result must be printed or returned in a variable

Returns:

a String only when dump=True

scapy.utils.hexedit(pktlist: _PacketIterable) PacketList[source]

Run hexedit on a list of packets, then return the edited packets.

scapy.utils.hexstr(p: Packet | AnyStr, onlyasc: int = 0, onlyhex: int = 0, color: bool = False) str[source]

Build a fancy tcpdump like hex from bytes.

scapy.utils.human_size(x: int, fmt: str = '.1f') str[source]

Convert a size in octets to a human string representation

scapy.utils.import_hexcap(input_string: str | None = None) bytes[source]

Imports a tcpdump like hexadecimal view

e.g: exported via hexdump() or tcpdump or wireshark’s “export as hex”

Parameters:

input_string – String containing the hexdump input to parse. If None, read from standard input.

scapy.utils.import_object(obj: str | None = None) Any[source]
scapy.utils.incremental_label(label: str = 'tag%05i', start: int = 0) Iterator[str][source]
scapy.utils.issubtype(C, B) bool[source]

Return whether C is a class and if it is a subclass of class B. When using a tuple as the second argument issubtype(X, (A, B, …)), is a shortcut for issubtype(X, A) or issubtype(X, B) or … (etc.).

scapy.utils.itom(x: int) int[source]
scapy.utils.lhex(x: Any) str[source]
scapy.utils.linehexdump(p: Packet | AnyStr, onlyasc: int = 0, onlyhex: int = 0, dump: bool = False) str | None[source]

Build an equivalent view of hexdump() on a single line

Note that setting both onlyasc and onlyhex to 1 results in a empty output

Parameters:
  • p – a Packet

  • onlyasc – 1 to display only the ascii view

  • onlyhex – 1 to display only the hexadecimal view

  • dump – print the view if False

Returns:

a String only when dump=True

scapy.utils.load_object(fname: str) Any[source]

unpickle a Python object

scapy.utils.long_converter(s: str) int[source]
scapy.utils.ltoa(x: int) str[source]
scapy.utils.mac2str(mac: str) bytes[source]
scapy.utils.make_lined_table(*args: Any, **kargs: Any) str | None[source]
scapy.utils.make_table(*args: Any, **kargs: Any) Any | None[source]
scapy.utils.make_tex_table(*args: Any, **kargs: Any) str | None[source]
scapy.utils.pretty_list(rtlst: List[Tuple[str | List[str], ...]], header: List[Tuple[str, ...]], sortBy: int | None = 0, borders: bool = False) str[source]

Pretty list to fit the terminal, and add header.

Parameters:
  • rtlst – a list of tuples. each tuple contains a value which can be either a string or a list of string.

  • sortBy – the column id (starting with 0) which will be used for ordering

  • borders – whether to put borders on the table or not

scapy.utils.randstring(length: int) bytes[source]

Returns a random string of length (length >= 0)

scapy.utils.rderf(filename: IO[bytes] | str, count: int = -1) PacketList[source]

Read a ERF file and return a packet list

Parameters:

count – read only <count> packets

scapy.utils.rdpcap(filename: IO[bytes] | str, count: int = -1) PacketList[source]

Read a pcap or pcapng file and return a packet list

Parameters:

count – read only <count> packets

scapy.utils.repr_hex(s: bytes) str[source]

Convert provided bitstring to a simple string of hex digits

scapy.utils.restart() None[source]

Restarts scapy

scapy.utils.sane(x: AnyStr, color: bool = False) str[source]
scapy.utils.save_object(fname: str, obj: Any) None[source]

Pickle a Python object

scapy.utils.str2mac(s: bytes) str[source]
scapy.utils.strand(s1: bytes, s2: bytes) bytes[source]

Returns the binary AND of the 2 provided strings s1 and s2. s1 and s2 must be of same length.

scapy.utils.strrot(s1: bytes, count: int, right: bool = True) bytes[source]

Rotate the binary by ‘count’ bytes

scapy.utils.strxor(s1: bytes, s2: bytes) bytes[source]

Returns the binary XOR of the 2 provided strings s1 and s2. s1 and s2 must be of same length.

scapy.utils.tcpdump(pktlist: IO[bytes] | None | str | _PacketIterable = None, dump: bool = False, getfd: bool = False, args: List[str] | None = None, flt: str | None = None, prog: Any | None = None, getproc: bool = False, quiet: bool = False, use_tempfile: Any | None = None, read_stdin_opts: Any | None = None, linktype: Any | None = None, wait: bool = True, _suppress: bool = False) Any[source]

Run tcpdump or tshark on a list of packets.

When using tcpdump on OSX (prog == conf.prog.tcpdump), this uses a temporary file to store the packets. This works around a bug in Apple’s version of tcpdump: http://apple.stackexchange.com/questions/152682/

Otherwise, the packets are passed in stdin.

This function can be explicitly enabled or disabled with the use_tempfile parameter.

When using wireshark, it will be called with -ki - to start immediately capturing packets from stdin.

Otherwise, the command will be run with -r - (which is correct for tcpdump and tshark).

This can be overridden with read_stdin_opts. This has no effect when use_tempfile=True, or otherwise reading packets from a regular file.

Parameters:
  • pktlist – a Packet instance, a PacketList instance or a list of Packet instances. Can also be a filename (as a string), an open file-like object that must be a file format readable by tshark (Pcap, PcapNg, etc.) or None (to sniff)

  • flt – a filter to use with tcpdump

  • dump – when set to True, returns a string instead of displaying it.

  • getfd – when set to True, returns a file-like object to read data from tcpdump or tshark from.

  • getproc – when set to True, the subprocess.Popen object is returned

  • args – arguments (as a list) to pass to tshark (example for tshark: args=[“-T”, “json”]).

  • prog – program to use (defaults to tcpdump, will work with tshark)

  • quiet – when set to True, the process stderr is discarded

  • use_tempfile – When set to True, always use a temporary file to store packets. When set to False, pipe packets through stdin. When set to None (default), only use a temporary file with tcpdump on OSX.

  • read_stdin_opts – When set, a list of arguments needed to capture from stdin. Otherwise, attempts to guess.

  • linktype – A custom DLT value or name, to overwrite the default values.

  • wait – If True (default), waits for the process to terminate before returning to Scapy. If False, the process will be detached to the background. If dump, getproc or getfd is True, these have the same effect as wait=False.

Examples:

>>> tcpdump([IP()/TCP(), IP()/UDP()])
reading from file -, link-type RAW (Raw IP)
16:46:00.474515 IP 127.0.0.1.20 > 127.0.0.1.80: Flags [S], seq 0, win 8192, length 0  # noqa: E501
16:46:00.475019 IP 127.0.0.1.53 > 127.0.0.1.53: [|domain]

>>> tcpdump([IP()/TCP(), IP()/UDP()], prog=conf.prog.tshark)
  1   0.000000    127.0.0.1 -> 127.0.0.1    TCP 40 20->80 [SYN] Seq=0 Win=8192 Len=0  # noqa: E501
  2   0.000459    127.0.0.1 -> 127.0.0.1    UDP 28 53->53 Len=0

To get a JSON representation of a tshark-parsed PacketList(), one can:

>>> import json, pprint
>>> json_data = json.load(tcpdump(IP(src="217.25.178.5",
...                                  dst="45.33.32.156"),
...                               prog=conf.prog.tshark,
...                               args=["-T", "json"],
...                               getfd=True))
>>> pprint.pprint(json_data)
[{u'_index': u'packets-2016-12-23',
  u'_score': None,
  u'_source': {u'layers': {u'frame': {u'frame.cap_len': u'20',
                                      u'frame.encap_type': u'7',
[...]
                                      },
                           u'ip': {u'ip.addr': u'45.33.32.156',
                                   u'ip.checksum': u'0x0000a20d',
[...]
                                   u'ip.ttl': u'64',
                                   u'ip.version': u'4'},
                           u'raw': u'Raw packet data'}},
  u'_type': u'pcap_file'}]
>>> json_data[0]['_source']['layers']['ip']['ip.ttl']
u'64'
scapy.utils.tdecode(pktlist: IO[bytes] | None | str | _PacketIterable, args: List[str] | None = None, **kwargs: Any) Any[source]

Run tshark on a list of packets.

Parameters:

args – If not specified, defaults to tshark -V.

See tcpdump() for more parameters.

scapy.utils.tex_escape(x: str) str[source]
scapy.utils.valid_ip(addr: str) bool[source]
scapy.utils.valid_ip6(addr: str) bool[source]
scapy.utils.valid_mac(mac: str) bool[source]
scapy.utils.valid_net(addr: str) bool[source]
scapy.utils.valid_net6(addr: str) bool[source]
scapy.utils.whois(ip_address: str) bytes[source]

Whois client for Python

scapy.utils.wireshark(pktlist: List[Packet], wait: bool = False, **kwargs: Any) Any | None[source]

Runs Wireshark on a list of packets.

See tcpdump() for more parameter description.

Note: this defaults to wait=False, to run Wireshark in the background.

scapy.utils.wrerf(filename: IO[bytes] | str, pkt: _PacketIterable, *args: Any, **kargs: Any) None[source]

Write a list of packets to a ERF file

Parameters:
  • filename – the name of the file to write packets to, or an open, writable file-like object. The file descriptor will be closed at the end of the call, so do not use an object you do not want to close (e.g., running wrerf(sys.stdout, []) in interactive mode will crash Scapy).

  • gz – set to 1 to save a gzipped capture

  • append – append packets to the capture file instead of truncating it

  • sync – do not bufferize writes to the capture file

scapy.utils.wrpcap(filename: IO[bytes] | str, pkt: _PacketIterable, *args: Any, **kargs: Any) None[source]

Write a list of packets to a pcap file

Parameters:
  • filename – the name of the file to write packets to, or an open, writable file-like object. The file descriptor will be closed at the end of the call, so do not use an object you do not want to close (e.g., running wrpcap(sys.stdout, []) in interactive mode will crash Scapy).

  • gz – set to 1 to save a gzipped capture

  • linktype – force linktype value

  • endianness – “<” or “>”, force endianness

  • sync – do not bufferize writes to the capture file

scapy.utils.wrpcapng(filename: str, pkt: _PacketIterable) None[source]

Write a list of packets to a pcapng file

Parameters:
  • filename – the name of the file to write packets to, or an open, writable file-like object. The file descriptor will be closed at the end of the call, so do not use an object you do not want to close (e.g., running wrpcapng(sys.stdout, []) in interactive mode will crash Scapy).

  • pkt – packets to write

scapy.utils.zerofree_randstring(length: int) bytes[source]

Returns a random string of length (length >= 0) without zero in it.