佳能sx220hs当年出厂价格_佳能SX220HS的使用技巧

佳能SX220HS的使用技巧

1、数码变焦关掉；

2、光学防抖打开；

3、晚上拍照尽量用手持拍夜景模式而不要打开闪光灯；

4、拍照时半按快门，出现绿色对焦框，对焦稳定后再次按下快门。

ipython常用方法说明

一直苦于python蹩脚的IDE，最近寻觅到一个非常优秀的python交互式解释器ipython， 再此总结下实际中常用到的方法：

特别说明下：本人为windows环境，所有命令都是相对windows的

自动补全

使用tab可以直接对已打出的对象或变量进行补全

魔术关键字

魔术关键字以%开头，如果automagic打开了，则不用输入%,否则需要，使用automagic可以切换状态

可以使用%magic参看所有魔术方法

env 显示环境变量

ed或edit 编辑一个文件并执行

ed -x filename 编辑文件不执行

edit 3:10 编辑3:10行的指令并执行

hist 显示历史纪录，可以用-n增加行号

hist 3:10 显示3-10行的历史纪录

bg function 把function函数放到后台执行

pwd 当前目录

pycat filename 语法高亮显示一个文件

macro name 1:10 把1:10行的代码设为name宏

save filename 1:10 把1:10行代码保存到文件中

time statement 计算一段代码执行时间

timeit statement 自动选择重复和循环次数计算一段代码执行时间

run filename 执行一个文件，如果希望防止执行的，需要增加if name == “main“:

autoindent 如果启用，粘贴的时候会自动缩进代码

reset 重置所有变量

Bash命令

cls 清除屏幕

colors

IPython -- An enhanced Interactive Python - Quick Reference Card================================================================obj?, obj?? : Get help, or more help for object (also works as ?obj, ??obj).?foo.*abc* : List names in 'foo' containing 'abc' in them.%magic : Information about IPython's 'magic' % functions.Magic functions are prefixed by % or %%, and typically take their argumentswithout parentheses, quotes or even commas for convenience. Line magics take asingle % and cell magics are prefixed with two %%.Example magic function calls:%alias d ls -F : 'd' is now an alias for 'ls -F'alias d ls -F : Works if 'alias' not a python namealist = %alias : Get list of aliases to 'alist'cd /usr/share : Obvious. cd -tab to choose from visited dirs.%cd?? : See help AND source for magic %cd%timeit x=10 : time the 'x=10' statement with high precision.%%timeit x=2**100x**100 : time 'x*100' with a setup of 'x=2**100'; setup code is not counted. This is an example of a cell magic.System commands:!cp a.txt b/ : System command escape, calls os.system()cp a.txt b/ : after %rehashx, most system commands work without !cp ${f}.txt $bar : Variable expansion in magics and system commandsfiles = !ls /usr : Capture sytem command outputfiles.s, files.l, files.n: "a b c", ['a','b','c'], 'anbnc'History:_i, _ii, _iii : Previous, next previous, next next previous input_i4, _ih[2:5] : Input history line 4, lines 2-4exec _i81 : Execute input history line #81 again%rep 81 : Edit input history line #81_, __, ___ : previous, next previous, next next previous output_dh : Directory history_oh : Output history%hist : Command history. '%hist -g foo' search history for 'foo'Autocall:f 1,2 : f(1,2) # Off by default, enable with %autocall magic./f 1,2 : f(1,2) (forced autoparen),f 1 2 : f("1","2");f 1 2 : f("1 2")Remember: TAB completion works in many contexts, not just file namesor python names.The following magic functions are currently available:%alias: Define an alias for a system command.%alias_magic: %alias_magic [-l] [-c] name target%autocall: Make functions callable without having to type parentheses. #%automagic: Make magic functions callable without having to type the initial %. #使用%automagic on(off)打开(关闭)automagic，打开后使用魔术方法不需要加%%autosave: Set the autosave interval in the notebook (in seconds).%bookmark: Manage IPython's bookmark system.%cd: #切换目录 Change the current working directory.%clear: #清除终端 Clear the terminal.%cls: Clear the terminal.%colors: Switch color scheme for prompts, info system and exception handlers. Currently implemented schemes: NoColor, Linux, LightBG. Color scheme names are not case-sensitive.%config: configure IPython%connect_info: Print information for connecting other clients to this kernel%debug: %debug [--breakpoint FILE:LINE] [statement [statement ...]]%dhist: Print your history of visited directories.%dirs: #返回当前目录 Return the current directory stack.%doctest_mode: Toggle doctest mode on and off.%ed: #打开文本编辑器 Alias for `%edit`.%edit: Bring up an editor and execute the resulting code.%env: #罗列环境变量 List environment variables.%gui: Enable or disable IPython GUI event loop integration.%guiref: Show a basic reference about the GUI Console.%hist: Alias for `%history`.%history: %history [-n] [-o] [-p] [-t] [-f FILENAME] [-g [PATTERN [PATTERN ...]]]%install_default_config: %install_default_config has been deprecated.%install_ext: Download and install an extension from a URL, e.g.::%install_profiles: %install_profiles has been deprecated.%killbgscripts: Kill all BG processes started by %%script and its family.%less: Show a file through the pager.%load: #载入指定python文件的当前源码 Load code into the current frontend.%load_ext: Load an IPython extension by its module name.%loadpy: Alias of `%load`%logoff: Temporarily stop logging.%logon: Restart logging.%logstart: Start logging anywhere in a session.%logstate: Print the status of the logging system.%logstop: Fully stop logging and close log file.%lsmagic: List currently available magic functions.%macro: Define a macro for future re-execution. It accepts ranges of history,%magic: Print information about the magic function system.%matplotlib: %matplotlib [gui]%more: Show a file through the pager.%notebook: %notebook [-e] [-f FORMAT] filename%page: Pretty print the object and display it through a pager.%pastebin: Upload code to Github's Gist paste bin, returning the URL.%pdb: Control the automatic calling of the pdb interactive debugger.%pdef: Print the call signature for any callable object.%pdoc: Print the docstring for an object.%pfile: Print (or run through pager) the file where an object is defined.%pinfo: Provide detailed information about an object.%pinfo2: Provide extra detailed information about an object.%popd: Change to directory popped off the top of the stack.%pprint: Toggle pretty printing on/off.%precision: Set floating point precision for pretty printing.%profile: Print your currently active IPython profile.%prun: Run a statement through the python code profiler.%psearch: Search for object in namespaces by wildcard.%psource: Print (or run through pager) the source code for an object.%pushd: Place the current dir on stack and change directory.%pwd: Return the current working directory path.%pycat: Show a syntax-highlighted file through a pager.%pylab: %pylab [--no-import-all] [gui]%qtconsole: Open a qtconsole connected to this kernel.%quickref: Show a quick reference sheet %recall: Repeat a command, or get command to input line for editing.%rehashx: Update the alias table with all executable files in $PATH.%reload_ext: Reload an IPython extension by its module name.%rep: Alias for `%recall`.%rerun: Re-run previous input%reset: Resets the namespace by removing all names defined by the user, if%reset_selective: Resets the namespace by removing names defined by the user.%run: Run the named file inside IPython as a program.%save: Save a set of lines or a macro to a given filename.%sc: Shell capture - run shell command and capture output (DEPRECATED use !).%store: Lightweight persistence for python variables.%sx: Shell execute - run shell command and capture output (!! is short-hand).%system: Shell execute - run shell command and capture output (!! is short-hand).%tb: Print the last traceback with the currently active exception mode.%time: #一个python表达式的执行时间 Time execution of a Python statement or expression.%timeit: Time execution of a Python statement or expression%unalias: Remove an alias%unload_ext: Unload an IPython extension by its module name.%who: Print all interactive variables, with some minimal formatting.%who_ls: Return a sorted list of all interactive variables.%whos: Like %who, but gives some extra information about each variable.%xdel: Delete a variable, trying to clear it from anywhere that%xmode: Switch modes for the exception handlers.%%!: Shell execute - run shell command and capture output (!! is short-hand).%%HTML: Alias for `%%html`.%%SVG: Alias for `%%svg`.%%bash: %%bash script magic%%capture: %capture [--no-stderr] [--no-stdout] [output]%%cmd: %%cmd script magic%%debug: %debug [--breakpoint FILE:LINE] [statement [statement ...]]%%file: Alias for `%%writefile`.%%html: Render the cell as a block of HTML%%javascript: Run the cell block of Javascript code%%latex: Render the cell as a block of latex%%perl: %%perl script magic%%powershell: %%powershell script magic%%prun: Run a statement through the python code profiler.%%pypy: %%pypy script magic%%python: %%python script magic%%python3: %%python3 script magic%%ruby: %%ruby script magic%%script: %shebang [--proc PROC] [--bg] [--err ERR] [--out OUT]%%sh: %%sh script magic%%svg: Render the cell as an SVG literal%%sx: Shell execute - run shell command and capture output (!! is short-hand).%%system: Shell execute - run shell command and capture output (!! is short-hand).%%time: Time execution of a Python statement or expression.%%timeit: Time execution of a Python statement or expression%%writefile: %writefile [-a] filename123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292

使用!做前缀可以执行shell命令，还可以用$来转换python变量，如下

for i in range(10):

s = “dir%s” % i

!mkdir $s

for i in !ls:

print i

特别的，如果普通的shell命令有的话，必须使用

的话，必须使用对原来的进行转义，如果原来是echo

进行转义，如果原来是echoPATH，需要使用shell时候，需要写成!echo $$PATH

打印对象属性

使用dir可以将对象属性打印出来，如

import os

dir(os)