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
|
\section{\module{readline} ---
GNU readline interface}
\declaremodule{builtin}{readline}
\platform{Unix}
\sectionauthor{Skip Montanaro}{skip@mojam.com}
\modulesynopsis{GNU readline support for Python.}
The \module{readline} module defines a number of functions to
facilitate completion and reading/writing of history files from the
Python interpreter. This module can be used directly or via the
\refmodule{rlcompleter} module. Settings made using
this module affect the behaviour of both the interpreter's interactive prompt
and the prompts offered by the \function{raw_input()} and \function{input()}
built-in functions.
The \module{readline} module defines the following functions:
\begin{funcdesc}{parse_and_bind}{string}
Parse and execute single line of a readline init file.
\end{funcdesc}
\begin{funcdesc}{get_line_buffer}{}
Return the current contents of the line buffer.
\end{funcdesc}
\begin{funcdesc}{insert_text}{string}
Insert text into the command line.
\end{funcdesc}
\begin{funcdesc}{read_init_file}{\optional{filename}}
Parse a readline initialization file.
The default filename is the last filename used.
\end{funcdesc}
\begin{funcdesc}{read_history_file}{\optional{filename}}
Load a readline history file.
The default filename is \file{\~{}/.history}.
\end{funcdesc}
\begin{funcdesc}{write_history_file}{\optional{filename}}
Save a readline history file.
The default filename is \file{\~{}/.history}.
\end{funcdesc}
\begin{funcdesc}{clear_history}{}
Clear the current history. (Note: this function is not available if
the installed version of GNU readline doesn't support it.)
\versionadded{2.4}
\end{funcdesc}
\begin{funcdesc}{get_history_length}{}
Return the desired length of the history file. Negative values imply
unlimited history file size.
\end{funcdesc}
\begin{funcdesc}{set_history_length}{length}
Set the number of lines to save in the history file.
\function{write_history_file()} uses this value to truncate the
history file when saving. Negative values imply unlimited history
file size.
\end{funcdesc}
\begin{funcdesc}{get_current_history_length}{}
Return the number of lines currently in the history. (This is different
from \function{get_history_length()}, which returns the maximum number of
lines that will be written to a history file.) \versionadded{2.3}
\end{funcdesc}
\begin{funcdesc}{get_history_item}{index}
Return the current contents of history item at \var{index}.
\versionadded{2.3}
\end{funcdesc}
\begin{funcdesc}{remove_history_item}{pos}
Remove history item specified by its position from the history.
\versionadded{2.4}
\end{funcdesc}
\begin{funcdesc}{replace_history_item}{pos, line}
Replace history item specified by its position with the given line.
\versionadded{2.4}
\end{funcdesc}
\begin{funcdesc}{redisplay}{}
Change what's displayed on the screen to reflect the current contents
of the line buffer. \versionadded{2.3}
\end{funcdesc}
\begin{funcdesc}{set_startup_hook}{\optional{function}}
Set or remove the startup_hook function. If \var{function} is specified,
it will be used as the new startup_hook function; if omitted or
\code{None}, any hook function already installed is removed. The
startup_hook function is called with no arguments just
before readline prints the first prompt.
\end{funcdesc}
\begin{funcdesc}{set_pre_input_hook}{\optional{function}}
Set or remove the pre_input_hook function. If \var{function} is specified,
it will be used as the new pre_input_hook function; if omitted or
\code{None}, any hook function already installed is removed. The
pre_input_hook function is called with no arguments after the first prompt
has been printed and just before readline starts reading input characters.
\end{funcdesc}
\begin{funcdesc}{set_completer}{\optional{function}}
Set or remove the completer function. If \var{function} is specified,
it will be used as the new completer function; if omitted or
\code{None}, any completer function already installed is removed. The
completer function is called as \code{\var{function}(\var{text},
\var{state})}, for \var{state} in \code{0}, \code{1}, \code{2}, ...,
until it returns a non-string value. It should return the next
possible completion starting with \var{text}.
\end{funcdesc}
\begin{funcdesc}{get_completer}{}
Get the completer function, or \code{None} if no completer function
has been set. \versionadded{2.3}
\end{funcdesc}
\begin{funcdesc}{get_begidx}{}
Get the beginning index of the readline tab-completion scope.
\end{funcdesc}
\begin{funcdesc}{get_endidx}{}
Get the ending index of the readline tab-completion scope.
\end{funcdesc}
\begin{funcdesc}{set_completer_delims}{string}
Set the readline word delimiters for tab-completion.
\end{funcdesc}
\begin{funcdesc}{get_completer_delims}{}
Get the readline word delimiters for tab-completion.
\end{funcdesc}
\begin{funcdesc}{add_history}{line}
Append a line to the history buffer, as if it was the last line typed.
\end{funcdesc}
\begin{seealso}
\seemodule{rlcompleter}{Completion of Python identifiers at the
interactive prompt.}
\end{seealso}
\subsection{Example \label{readline-example}}
The following example demonstrates how to use the
\module{readline} module's history reading and writing functions to
automatically load and save a history file named \file{.pyhist} from
the user's home directory. The code below would normally be executed
automatically during interactive sessions from the user's
\envvar{PYTHONSTARTUP} file.
\begin{verbatim}
import os
histfile = os.path.join(os.environ["HOME"], ".pyhist")
try:
readline.read_history_file(histfile)
except IOError:
pass
import atexit
atexit.register(readline.write_history_file, histfile)
del os, histfile
\end{verbatim}
The following example extends the \class{code.InteractiveConsole} class to
support history save/restore.
\begin{verbatim}
import code
import readline
import atexit
import os
class HistoryConsole(code.InteractiveConsole):
def __init__(self, locals=None, filename="<console>",
histfile=os.path.expanduser("~/.console-history")):
code.InteractiveConsole.__init__(self)
self.init_history(histfile)
def init_history(self, histfile):
readline.parse_and_bind("tab: complete")
if hasattr(readline, "read_history_file"):
try:
readline.read_history_file(histfile)
except IOError:
pass
atexit.register(self.save_history, histfile)
def save_history(self, histfile):
readline.write_history_file(histfile)
\end{verbatim}
|
