1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
:mod:`curses.ascii` --- Utilities for ASCII characters
======================================================
.. module:: curses.ascii
:synopsis: Constants and set-membership functions for ASCII characters.
.. moduleauthor:: Eric S. Raymond <esr@thyrsus.com>
.. sectionauthor:: Eric S. Raymond <esr@thyrsus.com>
**Source code:** :source:`Lib/curses/ascii.py`
--------------
The :mod:`curses.ascii` module supplies name constants for ASCII characters and
functions to test membership in various ASCII character classes. The constants
supplied are names for control characters as follows:
+---------------+----------------------------------------------+
| Name | Meaning |
+===============+==============================================+
| .. data:: NUL | |
+---------------+----------------------------------------------+
| .. data:: SOH | Start of heading, console interrupt |
+---------------+----------------------------------------------+
| .. data:: STX | Start of text |
+---------------+----------------------------------------------+
| .. data:: ETX | End of text |
+---------------+----------------------------------------------+
| .. data:: EOT | End of transmission |
+---------------+----------------------------------------------+
| .. data:: ENQ | Enquiry, goes with :const:`ACK` flow control |
+---------------+----------------------------------------------+
| .. data:: ACK | Acknowledgement |
+---------------+----------------------------------------------+
| .. data:: BEL | Bell |
+---------------+----------------------------------------------+
| .. data:: BS | Backspace |
+---------------+----------------------------------------------+
| .. data:: TAB | Tab |
+---------------+----------------------------------------------+
| .. data:: HT | Alias for :const:`TAB`: "Horizontal tab" |
+---------------+----------------------------------------------+
| .. data:: LF | Line feed |
+---------------+----------------------------------------------+
| .. data:: NL | Alias for :const:`LF`: "New line" |
+---------------+----------------------------------------------+
| .. data:: VT | Vertical tab |
+---------------+----------------------------------------------+
| .. data:: FF | Form feed |
+---------------+----------------------------------------------+
| .. data:: CR | Carriage return |
+---------------+----------------------------------------------+
| .. data:: SO | Shift-out, begin alternate character set |
+---------------+----------------------------------------------+
| .. data:: SI | Shift-in, resume default character set |
+---------------+----------------------------------------------+
| .. data:: DLE | Data-link escape |
+---------------+----------------------------------------------+
| .. data:: DC1 | XON, for flow control |
+---------------+----------------------------------------------+
| .. data:: DC2 | Device control 2, block-mode flow control |
+---------------+----------------------------------------------+
| .. data:: DC3 | XOFF, for flow control |
+---------------+----------------------------------------------+
| .. data:: DC4 | Device control 4 |
+---------------+----------------------------------------------+
| .. data:: NAK | Negative acknowledgement |
+---------------+----------------------------------------------+
| .. data:: SYN | Synchronous idle |
+---------------+----------------------------------------------+
| .. data:: ETB | End transmission block |
+---------------+----------------------------------------------+
| .. data:: CAN | Cancel |
+---------------+----------------------------------------------+
| .. data:: EM | End of medium |
+---------------+----------------------------------------------+
| .. data:: SUB | Substitute |
+---------------+----------------------------------------------+
| .. data:: ESC | Escape |
+---------------+----------------------------------------------+
| .. data:: FS | File separator |
+---------------+----------------------------------------------+
| .. data:: GS | Group separator |
+---------------+----------------------------------------------+
| .. data:: RS | Record separator, block-mode terminator |
+---------------+----------------------------------------------+
| .. data:: US | Unit separator |
+---------------+----------------------------------------------+
| .. data:: SP | Space |
+---------------+----------------------------------------------+
| .. data:: DEL | Delete |
+---------------+----------------------------------------------+
Note that many of these have little practical significance in modern usage. The
mnemonics derive from teleprinter conventions that predate digital computers.
The module supplies the following functions, patterned on those in the standard
C library:
.. function:: isalnum(c)
Checks for an ASCII alphanumeric character; it is equivalent to ``isalpha(c) or
isdigit(c)``.
.. function:: isalpha(c)
Checks for an ASCII alphabetic character; it is equivalent to ``isupper(c) or
islower(c)``.
.. function:: isascii(c)
Checks for a character value that fits in the 7-bit ASCII set.
.. function:: isblank(c)
Checks for an ASCII whitespace character; space or horizontal tab.
.. function:: iscntrl(c)
Checks for an ASCII control character (in the range 0x00 to 0x1f or 0x7f).
.. function:: isdigit(c)
Checks for an ASCII decimal digit, ``'0'`` through ``'9'``. This is equivalent
to ``c in string.digits``.
.. function:: isgraph(c)
Checks for ASCII any printable character except space.
.. function:: islower(c)
Checks for an ASCII lower-case character.
.. function:: isprint(c)
Checks for any ASCII printable character including space.
.. function:: ispunct(c)
Checks for any printable ASCII character which is not a space or an alphanumeric
character.
.. function:: isspace(c)
Checks for ASCII white-space characters; space, line feed, carriage return, form
feed, horizontal tab, vertical tab.
.. function:: isupper(c)
Checks for an ASCII uppercase letter.
.. function:: isxdigit(c)
Checks for an ASCII hexadecimal digit. This is equivalent to ``c in
string.hexdigits``.
.. function:: isctrl(c)
Checks for an ASCII control character (ordinal values 0 to 31).
.. function:: ismeta(c)
Checks for a non-ASCII character (ordinal values 0x80 and above).
These functions accept either integers or single-character strings; when the argument is a
string, it is first converted using the built-in function :func:`ord`.
Note that all these functions check ordinal bit values derived from the
character of the string you pass in; they do not actually know anything about
the host machine's character encoding.
The following two functions take either a single-character string or integer
byte value; they return a value of the same type.
.. function:: ascii(c)
Return the ASCII value corresponding to the low 7 bits of *c*.
.. function:: ctrl(c)
Return the control character corresponding to the given character (the character
bit value is bitwise-anded with 0x1f).
.. function:: alt(c)
Return the 8-bit character corresponding to the given ASCII character (the
character bit value is bitwise-ored with 0x80).
The following function takes either a single-character string or integer value;
it returns a string.
.. index::
single: ^ (caret); in curses module
single: ! (exclamation); in curses module
.. function:: unctrl(c)
Return a string representation of the ASCII character *c*. If *c* is printable,
this string is the character itself. If the character is a control character
(0x00--0x1f) the string consists of a caret (``'^'``) followed by the
corresponding uppercase letter. If the character is an ASCII delete (0x7f) the
string is ``'^?'``. If the character has its meta bit (0x80) set, the meta bit
is stripped, the preceding rules applied, and ``'!'`` prepended to the result.
.. data:: controlnames
A 33-element string array that contains the ASCII mnemonics for the thirty-two
ASCII control characters from 0 (NUL) to 0x1f (US), in order, plus the mnemonic
``SP`` for the space character.
|
