termformatters 0.2.1

Description:

termformatters 0.2.1

Terminal Formatters
Simple Python package for producing colored and formated terminal text.

Terminals traditionally take an input of bytes and display them as white
text on a black background. But if the input contains specific CSI
(Control Sequence Introducer) sequences then the terminal may alter
certain display properties of the text, such as the style or color.
Using styles and colors in console applications helps us analyze
information faster and focus on important parts of the displayed
information.
The package creates ANSI escape character sequences for changing the
color and style of the font, based on human-readable parameters like
black, green, italic etc.

ANSI Escape Codes for Terminal Graphics
The ANSI escape code
standard, formally
adopted as ISO/IEC
6429,
defines a series of control sequences. Each control sequence begins with
a Control Sequence Introducer (CSI), defined as an escape character
followed immediately by a bracket: ESC[. The ANSI ASCII standard
represents the escape ESC character by the decimal number 27 (33 in
octal, 1B in hexadecimal). The ESC[ is followed by any number
(including none) of “parameter bytes” in the range 0x30–0x3F (ASCII
0–9:;<=>?), then by any number of “intermediate bytes” in the range
0x20–0x2F (ASCII space and !"#$%&'()*+,-./), then finally by
a single “final byte” in the range 0x40–0x7E (ASCII
@A–Z[\]^_a–z{|}~`).
All common sequences just use the parameters as a series of
semicolon-separated numbers. Missing numbers are treated as 0 and no
parameters at all in ESC[m acts like a 0 reset code.


Select Graphic Rendition (SGR) parameters
The control sequence CSI n m, named Select Graphic Rendition
(SGR), sets display attributes. Several attributes can be set in the
same sequence, separated by semicolons. Each display attribute remains
in effect until a following occurrence of SGR resets it. If no codes are
given, CSI m is treated as CSI 0 m (reset / normal).
The package uses only basic parameters to control the font style and its
color. The most commonly used SGR parameters to control the font style
in the range (0-8) and the 8 actual colors within the ranges (30-37,
40-47, 90-97, 100-107) are defined by the ANSI standard. The package put
these parameters together to create a full SGR command.
The original specification only had 8 colors, and just gave them names.
The SGR parameters 30–37 selected the foreground color, while
40–47 selected the background. Quite a few terminals implemented
“bold” (SGR code 1) as a brighter color rather than a different
font, thus providing 8 additional foreground colors. Usually you could
not get these as background colors, though sometimes inverse video (SGR
code 7) would allow that. Examples: to get black letters on white
background use ESC[30;47m, to get red use ESC[31m, to get bright
red use ESC[1;31m. To reset colors to their defaults, use
ESC[39;49m (not supported on some terminals), or reset all
attributes with ESC[0m. Later terminals added the ability to
directly specify the “bright” colors with 90–97 and 100–107.
The following diagram shows the complete text style and color rendering
scheme.

The package supports the parameters shown in the tables below:

Font Styles


Parameter
Name
Note



0
Reset or normal
All attributes off

1
Bold or increased
intensity
As with faint, the color
change is a PC (SCO/CGA)
invention

2
Faint, decreased
intensity, or dim
May be implemented as a
light font weight like
bold

3
Italic
Not widely supported.
Sometimes treated as
inverse or blink

4
Underline
Style extensions exist
for Kitty, VTE, mintty
and iTerm2

5
Blink or Slow blink
Sets blinking to less
than 150 times per minute

7
Negative, Reverse or
invert
Swap foreground and
background colors;
inconsistent emulation

8
Conceal or hide
Not widely supported





Foreground/Background Colors


Foreground
Background
Name



30
40
Black

31
41
Red

32
42
Green

33
43
Yellow

34
44
Blue

35
45
Magenta

36
46
Cyan

37
47
White

90
100
Black Bright or Grey

91
101
Red Bright

92
102
Green Bright

93
103
Yellow Bright

94
104
Blue Bright

95
105
Magenta Bright

96
106
Cyan Bright

97
107
Bright



Test scripts in the source code repository print formatted/colored
tables using supported ANSI sequences. The following styles and colors
works with most terminal applications.


The package has no requirements other than the standard library.



Usage
How to use the module in your own python code:
from termformatters import StyleFormatters
from termformatters import ForegroundFormatters
from termformatters import BackgroundFormatters

"""Creating Formatters Instances"""
S = StyleFormatters()
FG = ForegroundFormatters()
BG = BackgroundFormatters()

print(FG.green("Printing `Green` colored text"))
print(FG.cyan("Printing `Cyan` colored text"))
print(
S.bold(
FG.white_bright(
"Printing `Bold` and `White Bright` text"
)
)
)
print(
FG.yellow(
BG.blue_bright(
"Printing `Yellow` text on `Blue` background"
)
)
)


References

ANSI escape code
standard
ISO/IEC
6429