readline
— GNU readline 接口
¶
The
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
rlcompleter
module. Settings made using this module affect the behaviour of both the interpreter’s interactive prompt and the prompts offered by the built-in
input()
函数。
注意
On MacOS X the
readline
module can be implemented using the
libedit
library instead of GNU readline.
配置文件对于
libedit
异于 GNU readline。若以编程方式加载配置字符串，可以校验文本 libedit 在
readline.__doc__
以区分 GNU readline 和 libedit。
The
readline
模块定义了下列函数：
readline.
parse_and_bind
(
string
)
¶
Parse and execute single line of a readline init file.
readline.
get_line_buffer
(
)
¶
Return the current contents of the line buffer.
readline.
insert_text
(
string
)
¶
Insert text into the command line.
readline.
read_init_file
(
[
filename
]
)
¶
Parse a readline initialization file. The default filename is the last filename used.
readline.
read_history_file
(
[
filename
]
)
¶
Load a readline history file. The default filename is
~/.history
.
readline.
write_history_file
(
[
filename
]
)
¶
Save a readline history file. The default filename is
~/.history
.
readline.
clear_history
(
)
¶
Clear the current history. (Note: this function is not available if the installed version of GNU readline doesn’t support it.)
readline.
get_history_length
(
)
¶
Return the desired length of the history file. Negative values imply unlimited history file size.
readline.
set_history_length
(
length
)
¶
Set the number of lines to save in the history file.
write_history_file()
uses this value to truncate the history file when saving. Negative values imply unlimited history file size.
readline.
get_current_history_length
(
)
¶
Return the number of lines currently in the history. (This is different from
get_history_length()
, which returns the maximum number of lines that will be written to a history file.)
readline.
get_history_item
(
index
)
¶
Return the current contents of history item at index .
readline.
remove_history_item
(
pos
)
¶
Remove history item specified by its position from the history.
readline.
replace_history_item
(
pos
,
line
)
¶
Replace history item specified by its position with the given line.
readline.
redisplay
(
)
¶
Change what’s displayed on the screen to reflect the current contents of the line buffer.
readline.
set_startup_hook
(
[
function
]
)
¶
Set or remove the startup_hook function. If
function
is specified, it will be used as the new startup_hook function; if omitted or
None
, any hook function already installed is removed. The startup_hook function is called with no arguments just before readline prints the first prompt.
readline.
set_pre_input_hook
(
[
function
]
)
¶
Set or remove the pre_input_hook function. If
function
is specified, it will be used as the new pre_input_hook function; if omitted or
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.
readline.
set_completer
(
[
function
]
)
¶
Set or remove the completer function. If
function
is specified, it will be used as the new completer function; if omitted or
None
, any completer function already installed is removed. The completer function is called as
function(text, state)
, for
state
in
0
,
1
,
2
, ..., until it returns a non-string value. It should return the next possible completion starting with
text
.
readline.
get_completer
(
)
¶
获取补全器函数，或
None
若没有设置补全器函数。
readline.
get_completion_type
(
)
¶
Get the type of completion being attempted.
readline.
get_begidx
(
)
¶
Get the beginning index of the readline tab-completion scope.
readline.
get_endidx
(
)
¶
Get the ending index of the readline tab-completion scope.
readline.
set_completer_delims
(
string
)
¶
Set the readline word delimiters for tab-completion.
readline.
get_completer_delims
(
)
¶
Get the readline word delimiters for tab-completion.
readline.
set_completion_display_matches_hook
(
[
function
]
)
¶
Set or remove the completion display function. If
function
is specified, it will be used as the new completion display function; if omitted or
None
, any completion display function already installed is removed. The completion display function is called as
function(substitution, [matches], longest_match_length)
once each time matches need to be displayed.
readline.
add_history
(
line
)
¶
Append a line to the history buffer, as if it was the last line typed.
另请参阅
rlcompleter
以下范例演示如何使用
readline
模块的历史读取和写入功能，以自动加载和保存历史文件命名
.python_history
从用户 Home (主) 目录。以下代码在交互式会话期间，通常会自动执行从用户的
PYTHONSTARTUP
文件。
import atexit import os import readline histfile = os.path.join(os.path.expanduser("~"), ".python_history") try: readline.read_history_file(histfile) except FileNotFoundError: pass atexit.register(readline.write_history_file, histfile)
此代码实际会自动运行，当 Python 运行在 交互模式 (见 readline 配置 ).
以下范例扩展了
code.InteractiveConsole
类以支持历史的保存/还原。
import atexit import code import os import readline class HistoryConsole(code.InteractiveConsole): def __init__(self, locals=None, filename="<console>", histfile=os.path.expanduser("~/.console-history")): code.InteractiveConsole.__init__(self, locals, filename) 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 FileNotFoundError: pass atexit.register(self.save_history, histfile) def save_history(self, histfile): readline.write_history_file(histfile)