formatters#

Models for controlling the text and visual formatting of tick labels on Bokeh plot axes.

class BasicTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Display tick values from continuous ranges as “basic numbers”, using scientific notation when appropriate by default.

power_limit_high#

Limit the use of scientific notation to when:

log(x) >= power_limit_high
power_limit_low#

Limit the use of scientific notation to when:

log(x) <= power_limit_low
precision#

How many digits of precision to display in tick labels.

use_scientific#

Whether to ever display scientific notation. If True, then when to use scientific notation is controlled by power_limit_low and power_limit_high.

class CategoricalTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Display tick values from categorical ranges as string values.

class CustomJSTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Display tick values that are formatted by a user-defined function.

Warning

The explicit purpose of this Bokeh Model is to embed raw JavaScript code for a browser to execute. If any part of the code is derived from untrusted user inputs, then you must take appropriate care to sanitize the user input prior to passing to Bokeh.

args#

A mapping of names to Python objects. In particular those can be bokeh’s models. These objects are made available to the formatter’s code snippet as the values of named parameters to the callback.

code#

A snippet of JavaScript code that reformats a single tick to the desired format. The variable tick will contain the unformatted tick value and can be expected to be present in the code snippet namespace at render time.

Additionally available variables are:

  • ticks, an array of all axis ticks as positioned by the ticker,

  • index, the position of tick within ticks, and

  • the keys of args mapping, if any.

Finding yourself needing to cache an expensive ticks-dependent computation, you can store it on the this variable.

Example

code = '''
this.precision = this.precision || (ticks.length > 5 ? 1 : 2);
return Math.floor(tick) + " + " + (tick % 1).toFixed(this.precision);
'''
class DatetimeTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

A TickFormatter for displaying datetime values nicely across a range of scales.

DatetimeTickFormatter has the following properties (listed together with their default values) that can be used to control the formatting of axis ticks at different scales:

Scale

Format

1st Context

2nd Context

microseconds

%fus

%T

%b %d, %Y

milliseconds

%3Nms

%T

%b %d, %Y

seconds

%T

%b %d, %Y

minsec

%T

%b %d, %Y

minutes

%H:%M

%b %d, %Y

hourmin

%H:%M

%b %d, %Y

hours

%H:%M

%b %d, %Y

days

%b %d

%Y

months

%b %Y

years

%Y

Each scale property can be set to format or list of formats to use for formatting datetime tick values that fall in that “time scale”. By default, only the first format string passed for each time scale will be used. By default, all leading zeros are stripped away from the formatted labels.

This list of supported strftime formats is reproduced below.

%a

The abbreviated name of the day of the week according to the current locale.

%A

The full name of the day of the week according to the current locale.

%b

The abbreviated month name according to the current locale.

%B

The full month name according to the current locale.

%c

The preferred date and time representation for the current locale.

%C

The century number (year/100) as a 2-digit integer.

%d

The day of the month as a decimal number (range 01 to 31).

%D

Equivalent to %m/%d/%y. (Americans should note that in many other countries %d/%m/%y is rather common. This means that in international context this format is ambiguous and should not be used.)

%e

Like %d, the day of the month as a decimal number, but a leading zero is replaced by a space.

%f

Microsecond as a decimal number, zero-padded on the left (range 000000-999999). This is an extension to the set of directives available to timezone.

%F

Equivalent to %Y-%m-%d (the ISO 8601 date format).

%G

The ISO 8601 week-based year with century as a decimal number. The 4-digit year corresponding to the ISO week number (see %V). This has the same format and value as %Y, except that if the ISO week number belongs to the previous or next year, that year is used instead.

%g

Like %G, but without century, that is, with a 2-digit year (00-99).

%h

Equivalent to %b.

%H

The hour as a decimal number using a 24-hour clock (range 00 to 23).

%I

The hour as a decimal number using a 12-hour clock (range 01 to 12).

%j

The day of the year as a decimal number (range 001 to 366).

%k

The hour (24-hour clock) as a decimal number (range 0 to 23). Single digits are preceded by a blank. See also %H.

%l

The hour (12-hour clock) as a decimal number (range 1 to 12). Single digits are preceded by a blank. See also %I.

%m

The month as a decimal number (range 01 to 12).

%M

The minute as a decimal number (range 00 to 59).

%n

A newline character. Bokeh text does not currently support newline characters.

%N

Nanosecond as a decimal number, zero-padded on the left (range 000000000-999999999). Supports a padding width specifier, i.e. %3N displays 3 leftmost digits. However, this is only accurate to the millisecond level of precision due to limitations of timezone.

%p

Either “AM” or “PM” according to the given time value, or the corresponding strings for the current locale. Noon is treated as “PM” and midnight as “AM”.

%P

Like %p but in lowercase: “am” or “pm” or a corresponding string for the current locale.

%r

The time in a.m. or p.m. notation. In the POSIX locale this is equivalent to %I:%M:%S %p.

%R

The time in 24-hour notation (%H:%M). For a version including the seconds, see %T below.

%s

The number of seconds since the Epoch, 1970-01-01 00:00:00+0000 (UTC).

%S

The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds.)

%t

A tab character. Bokeh text does not currently support tab characters.

%T

The time in 24-hour notation (%H:%M:%S).

%u

The day of the week as a decimal, range 1 to 7, Monday being 1. See also %w.

%U

The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01. See also %V and %W.

%V

The ISO 8601 week number (see NOTES) of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the new year. See also %U and %W.

%w

The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.

%W

The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01.

%x

The preferred date representation for the current locale without the time.

%X

The preferred time representation for the current locale without the date.

%y

The year as a decimal number without a century (range 00 to 99).

%Y

The year as a decimal number including the century.

%z

The +hhmm or -hhmm numeric timezone (that is, the hour and minute offset from UTC).

%Z

The timezone name or abbreviation.

%%

A literal ‘%’ character.

Warning

The client library BokehJS uses the timezone library to format datetimes. The inclusion of the list below is based on the claim that timezone makes to support “the full complement of GNU date format specifiers.” However, this claim has not been tested exhaustively against this list. If you find formats that do not function as expected, please submit a GitHub issue, so that the documentation can be updated appropriately.

boundary_scaling#

Whether to scale up ticks that are right at the boundary of the next higher resolution of time. E.g. at the hours scale a tick sequence of [“00h”, “06h”, “12h”, 18h”, “00h”] will see a scale up of the “00h” ticks as they are on boundary of the days scale: [“06/08”, “06h”, “12h”, 18h”, “06/09”]

context#

A format for adding context to the tick or ticks specified by context_which. Valid values are:

  • None, no context is added

  • A standard DatetimeTickFormatter format string, the single format is used across all scales

  • Another DatetimeTickFormatter instance, to have scale-dependent context

context_location#

Relative to the tick label text baseline, where the context should be rendered. Valid values are: “below”, “above”, “left”, and “right”.

context_which#

Which tick or ticks to add a formatted context string to. Valid values are: “start”, “end”, “center”, and “all”.

days#

Formats for displaying datetime values in the days range.

See the DatetimeTickFormatter help for a list of all supported formats.

hide_repeats#

Whether repeated formatted tick values will be suppressed.

For example, an initial set of ticks ["06/07", "06/07", "06/07", "06/08", "06/08"] will become ["06/07", "", "", "06/08", ""]. Only the base label, without any additional context, is considered when determining repeats. If the context itself is a DatetimeTickFormatter, then this property may also be set for the context separately, if desired.

hourmin#

Formats for displaying datetime values in the hourmin (for combined hours and minutes) range.

See the DatetimeTickFormatter help for a list of all supported formats.

hours#

Formats for displaying datetime values in the hours range.

See the DatetimeTickFormatter help for a list of all supported formats.

microseconds#

Formats for displaying datetime values in the microseconds range.

See the DatetimeTickFormatter help for a list of all supported formats.

milliseconds#

Formats for displaying datetime values in the milliseconds range.

See the DatetimeTickFormatter help for a list of all supported formats.

minsec#

Formats for displaying datetime values in the minsec (for combined minutes and seconds) range.

See the DatetimeTickFormatter help for a list of all supported formats.

minutes#

Formats for displaying datetime values in the minutes range.

See the DatetimeTickFormatter help for a list of all supported formats.

months#

Formats for displaying datetime values in the months range.

See the DatetimeTickFormatter help for a list of all supported formats.

seconds#

Formats for displaying datetime values in the seconds range.

See the DatetimeTickFormatter help for a list of all supported formats.

strip_leading_zeros#

Whether to strip any leading zeros in the formatted ticks.

Valid values are:

  • True or False (default) to set stripping across all resolutions.

  • A sequence of resolution types, e.g. ["microseconds", "milliseconds"], to enable scale-dependent stripping of leading zeros.

years#

Formats for displaying datetime values in the years range.

See the DatetimeTickFormatter help for a list of all supported formats.

class LogTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Display tick values from continuous ranges as powers of some base.

Most often useful in conjunction with a LogTicker.

min_exponent#

Minimum exponent to format in scientific notation. If not zero all ticks in range from base^-min_exponent to base^min_exponent are displayed without exponential notation.

ticker#

The corresponding LogTicker, used to determine the correct base to use. If unset, the formatter will use base 10 as a default.

class MercatorTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

A TickFormatter for values in WebMercator units.

Some map plot types internally use WebMercator to describe coordinates, plot bounds, etc. These units are not very human-friendly. This tick formatter will convert WebMercator units into Latitude and Longitude for display on axes.

dimension#

Specify whether to format ticks for Latitude or Longitude.

Projected coordinates are not separable, computing Latitude and Longitude tick labels from Web Mercator requires considering coordinates from both dimensions together. Use this property to specify which result should be used for display.

Typically, if the formatter is for an x-axis, then dimension should be "lon" and if the formatter is for a y-axis, then the dimension should be “lat”`.

In order to prevent hard to debug errors, there is no default value for dimension. Using an un-configured MercatorTickFormatter will result in a validation error and a JavaScript console error.

class NumeralTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Tick formatter based on a human-readable format string.

format#

The number format, as defined in the following tables:

NUMBERS:

Number

Format

String

10000

‘0,0.0000’

10,000.0000

10000.23

‘0,0’

10,000

10000.23

‘+0,0’

+10,000

-10000

‘0,0.0’

-10,000.0

10000.1234

‘0.000’

10000.123

10000.1234

‘0[.]00000’

10000.12340

-10000

‘(0,0.0000)’

(10,000.0000)

-0.23

‘.00’

-.23

-0.23

‘(.00)’

(.23)

0.23

‘0.00000’

0.23000

0.23

‘0.0[0000]’

0.23

1230974

‘0.0a’

1.2m

1460

‘0 a’

1 k

-104000

‘0a’

-104k

1

‘0o’

1st

52

‘0o’

52nd

23

‘0o’

23rd

100

‘0o’

100th

CURRENCY:

Number

Format

String

1000.234

‘$0,0.00’

$1,000.23

1000.2

‘0,0[.]00 $’

1,000.20 $

1001

‘$ 0,0[.]00’

$ 1,001

-1000.234

‘($0,0)’

($1,000)

-1000.234

‘$0.00’

-$1000.23

1230974

‘($ 0.00 a)’

$ 1.23 m

BYTES:

Number

Format

String

100

‘0b’

100B

2048

‘0 b’

2 KB

7884486213

‘0.0b’

7.3GB

3467479682787

‘0.000 b’

3.154 TB

PERCENTAGES:

Number

Format

String

1

‘0%’

100%

0.974878234

‘0.000%’

97.488%

-0.43

‘0 %’

-43 %

0.43

‘(0.000 %)’

43.000 %

TIME:

Number

Format

String

25

‘00:00:00’

0:00:25

238

‘00:00:00’

0:03:58

63846

‘00:00:00’

17:44:06

For the complete specification, see http://numbrojs.com/format.html

language#

The language to use for formatting language-specific features (e.g. thousands separator).

rounding#

Rounding functions (round, floor, ceil) and their synonyms (nearest, rounddown, roundup).

class PrintfTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

Tick formatter based on a printf-style format string.

format#

the placeholder in the format string is marked by % and is followed by one or more of these elements, in this order:

  • An optional + sign

    Causes the result to be preceded with a plus or minus sign on numeric values. By default, only the - sign is used on negative numbers.

  • An optional padding specifier

    Specifies what (if any) character to use for padding. Possible values are 0 or any other character preceded by a ' (single quote). The default is to pad with spaces.

  • An optional - sign

    Causes sprintf to left-align the result of this placeholder. The default is to right-align the result.

  • An optional number

    Specifies how many characters the result should have. If the value to be returned is shorter than this number, the result will be padded.

  • An optional precision modifier

    Consists of a . (dot) followed by a number, specifies how many digits should be displayed for floating point numbers. When used on a string, it causes the result to be truncated.

  • A type specifier

    Can be any of:

    • % — yields a literal % character

    • b — yields an integer as a binary number

    • c — yields an integer as the character with that ASCII value

    • d or i — yields an integer as a signed decimal number

    • e — yields a float using scientific notation

    • u — yields an integer as an unsigned decimal number

    • f — yields a float as is

    • o — yields an integer as an octal number

    • s — yields a string as is

    • x — yields an integer as a hexadecimal number (lower-case)

    • X — yields an integer as a hexadecimal number (upper-case)

Type:

The number format, as defined as follows

class TickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

A base class for all tick formatter types.

Note

This is an abstract base class used to help organize the hierarchy of Bokeh model types. It is not useful to instantiate on its own.

class TimedeltaTickFormatter(*args: Any, id: ID | None = None, **kwargs: Any)[source]#

A TickFormatter for displaying timedelta values nicely across a range of scales. The largest scale for differentiating between formats is “days”, as the conversion from “days” to “months” or “years” is not well defined.

TimedeltaTickFormatter has the following properties (listed together with their default values) that can be used to control the formatting of axis ticks at different scales:

Scale

Format

1st Context

2nd Context

nanoseconds

%NSns

%H:%M:%S.%MS%US

%d days

microseconds

%USus

%H:%M:%S.%MS

%d days

milliseconds

%MSms

%H:%M:%S

%d days

seconds

%H:%M:%S

%d days

minsec

%H:%M:%S

%d days

minutes

%H:%M

%d days

hourmin

%H:%M

%d days

hours

%H:%M

%d days

days

%d days

Each scale property can be set to format or list of formats to use for formatting timedelta tick values that fall in that “time scale”. By default, only the first format string passed for each time scale will be used. By default, leading zeros are stripped away from the formatted labels for the time scales nanoseconds, microseconds and milliseconds.

This list of supported formats is reproduced below. In general formats with an uppercase letter refer to the time passed since the next last larger time format (e.g. minutes since the last hour). On the other hand formats with a lowercase letter corresponds to the overall completed time passed (3.6 days becomes 3 days).

%NS

Nanoseconds since last microsecond as a decimal number, zero-padded on the left (range 000 to 999). Warning: Due to floating point precision, ticks may be formatted incorrectly if the overall timedelta is rather large (>10days).

%ns

Overall completed nanoseconds. Warning: Due to floating point precision, ticks may be formatted incorrectly if the overall timedelta is rather large (>10days).

%US

Microseconds since last millisecond as a decimal number, zero-padded on the left (range 000 to 999).

%us

Overall completed microseconds.

%MS

Milliseconds since last second as a decimal number, zero-padded on the left (range 000 to 999).

%ms

Overall completed milliseconds.

%S

Seconds since last minute as a decimal number, zero-padded on the left (range 00 to 59).

%s

Overall completed seconds.

%M

Minutes since last hour as a decimal number, zero-padded on the left (range 00 to 59).

%m

Overall completed minutes.

%H

Hours since last day as a decimal number, zero-padded on the left (range 00 to 23).

%h

Overall completed hours.

%d

Overall completed days.
context#

A format for adding context to the tick or ticks specified by context_which. Valid values are:

  • None, no context is added

  • A standard TimedeltaTickFormatter format string, the single format is used across all scales

  • Another TimedeltaTickFormatter instance, to have scale-dependent context

context_location#

Relative to the tick label text baseline, where the context should be rendered. Valid values are: “below”, “above”, “left”, and “right”.

context_which#

Which tick or ticks to add a formatted context string to. Valid values are: “start”, “end”, “center”, and “all”.

days#

Formats for displaying timedelta values in the days range.

See the TimedeltaTickFormatter help for a list of all supported formats.

hide_repeats#

Whether repeated formatted tick values will be suppressed.

For example, an initial set of ticks ["06:07", "06:07", "06:07", "06:08", "06:08"] will become ["06:07", "", "", "06:08", ""]. Only the base label, without any additional context, is considered when determining repeats. If the context itself is a TimedeltaTickFormatter, then this property may also be set for the context separately, if desired.

hourmin#

Formats for displaying timedelta values in the hourmin (for combined hours and minutes) range.

See the TimedeltaTickFormatter help for a list of all supported formats.

hours#

Formats for displaying timedelta values in the hours range.

See the TimedeltaTickFormatter help for a list of all supported formats.

microseconds#

Formats for displaying timedelta values in the microseconds range.

See the TimedeltaTickFormatter help for a list of all supported formats.

milliseconds#

Formats for displaying timedelta values in the milliseconds range.

See the TimedeltaTickFormatter help for a list of all supported formats.

minsec#

Formats for displaying timedelta values in the minsec (for combined minutes and seconds) range.

See the TimedeltaTickFormatter help for a list of all supported formats.

minutes#

Formats for displaying timedelta values in the minutes range.

See the TimedeltaTickFormatter help for a list of all supported formats.

nanoseconds#

Formats for displaying timedelta values in the nanoseconds range.

See the TimedeltaTickFormatter help for a list of all supported formats.

seconds#

Formats for displaying timedelta values in the seconds range.

See the TimedeltaTickFormatter help for a list of all supported formats.

strip_leading_zeros#

Whether to strip any leading zeros in the formatted ticks.

Valid values are:

  • True or False (default) to set stripping across all resolutions.

  • A sequence of resolution types, e.g. ["microseconds", "milliseconds"], to enable scale-dependent stripping of leading zeros.

RELATIVE_DATETIME_CONTEXT() → DatetimeTickFormatter[source]#
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