Python常用工具¶
IPython¶
通过%quickref可以查看功能导览，通过%lsmagic可以列出ipython中支持的魔法函数:
In [9]: %lsmagic
Out[9]:
Available line magics:
%alias %alias_magic %autoawait %autocall %autoindent %automagic %bookmark %cat %cd %clear
%colors %conda %config %cp %cpaste %debug %dhist %dirs %doctest_mode %ed %edit %env %gui %hist %history %killbgscripts %ldir %less %lf %lk %ll %load %load_ext %loadpy %logoff
%logon %logstart %logstate %logstop %ls %lsmagic %lx %macro %magic %man %matplotlib %mkdir %more %mv %notebook %page %paste %pastebin %pdb %pdef %pdoc %pfile %pinfo %pinfo2 %pip %popd %pprint %precision %prun %psearch %psource %pushd %pwd %pycat %pylab %quickref %recall %rehashx %reload_ext %rep %rerun %reset %reset_selective %rm %rmdir %run %save %sc %set_env %store %sx %system %tb %time %timeit %unalias %unload_ext %who %who_ls %whos
%xdel %xmode
Available cell magics:
%%! %%HTML %%SVG %%bash %%capture %%debug %%file %%html %%javascript %%js %%latex %%markdown %%perl %%prun %%pypy %%python %%python2 %%python3 %%ruby %%script %%sh %%svg %%sx %%system %%time %%timeit %%writefile
?alias来查看它的具体使用方法。单个%表示执行当前行的内容，%%用于支持把多行内容作用于该魔法函数。
自省¶
在ipython中，通常使用?<object>的方式查看一个对象是什么，当输入某个对象后可以按下tab键查看其成员，通过%pdoc可查看其docstring，%psource可查看某个目标对象的源码(如果对象是module，需要用%pfile)，%who和%whos查看当前环境中的对象列表。
In [1]: import demo
In [2]: ?demo
Type: module
String form: <module 'demo' from '/home/hejl/demo.py'>
File: ~/demo.py
Docstring: test for doc module
In [3]: %pdoc demo
Class docstring:
test for doc module
In [4]: %psource demo.b
def b():
print("helloworld!")
In [5]: %pfile demo
"""
test for doc module
"""
a = 1
def b():
print("helloworld!")
In [6]: c = 2
In [7]: %who
c demo
In [8]: %whos
Variable Type Data/Info
------------------------------
c int 2
demo module <module 'demo' from '/home/hejl/demo.py'>
搜索¶
ipython支持搜索可用的函数，以及当前环境下的对象:
In [1]: import sys
In [2]: ?sys.get*
sys.get_asyncgen_hooks
sys.get_coroutine_wrapper
sys.getallocatedblocks
sys.getcheckinterval
sys.getdefaultencoding
sys.getdlopenflags
sys.getfilesystemencodeerrors
sys.getfilesystemencoding
sys.getprofile
sys.getrecursionlimit
sys.getrefcount
sys.getsizeof
sys.getswitchinterval
sys.gettrace
In [3]: ?sys.get*of
sys.getsizeof
In [4]: ?s*
set
setattr
slice
sorted
staticmethod
str
sum
super
sys
历史¶
通过%history -n可用查看在ipython中全部输入的历史，也可以通过_i查看上一个，_ii和_iii查看上两个和三个，_i<n>查看上n个:
In [6]: _i2
Out[6]: '?sys.get*'
In [7]: %history -n
1: import sys
2: ?sys.get*
3: ?sys.get*of
4: ?s *
5: ?s*
6: _i2
7: %history -n
In [8]: _i, _ii, _iii
Out[8]: ('%history -n', '_i2', '?s*')
还可以把历史命令中的某些行编写为一个宏，通过宏可以重复调用，下例中把第9至第10行、外加第12行编写入了一个宏:
In [9]: x,y=1,2
In [10]: print(x+y)
3
In [11]: y=10
In [12]: print(x+y)
11
In [13]: %macro tes 9-10 12
Macro `tes` created. To execute, type its name (without quotes).
=== Macro contents: ===
x,y=1,2
print(x+y)
print(x+y)
In [14]: tes
3
3
还可以使用%save把宏或者某些行保存在一个文件中:
In [15]: %save test.py tes
The following commands were written to file `test.py`:
x,y=1,2
print(x+y)
print(x+y)
In [16]: %save test.py 9-10
File `test.py` exists. Overwrite (y/[N])? y
The following commands were written to file `test.py`:
x,y=1,2
print(x+y)
命令¶
可以通过!执行shell中的命令，命令执行结果可以直接赋值给python变量，也可以将python变量传入shell:
In [26]: !ls
6.824 basic dump.rdb get-pip.py my_git test.py
MIT-6.824 cliu8siteprivate.key fastapi-vue-cms helloworld.key practise-go
__pycache__ demo.py flask-shop hjlarry.github.io practise-py
In [27]: a = !ls
In [28]: a
Out[28]:
['6.824',
'MIT-6.824',
'__pycache__',
...]
In [31]: x=100
In [32]: !echo "python.x={x+20}"
python.x=120
内置模块¶
查看包路径¶
~/projects » python3 -m site
sys.path = [
'/Users/hejl/projects',
'/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python38.zip',
'/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8',
'/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/lib-dynload',
'/usr/local/lib/python3.8/site-packages',
'/usr/local/Cellar/protobuf/3.12.3/libexec/lib/python3.8/site-packages',
'/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages',
]
USER_BASE: '/Users/hejl/Library/Python/3.8' (doesn't exist)
USER_SITE: '/Users/hejl/Library/Python/3.8/lib/python/site-packages' (doesn't exist)
ENABLE_USER_SITE: True
格式化json¶
~/projects » cat test.json
{"_id":"5f12d319624e57e27d1291fe","index":0,"name":"MasseySaunders","gender":"male","company":"TALAE","email":"masseysaunders@talae.com","phone":"+1(853)508-3237","address":"246IndianaPlace,Glenbrook,Iowa,3896","registered":"2017-02-06T06:42:20-08:00","latitude":-10.269827,"longitude":-103.12419,"friends":[{"id":0,"name":"DorotheaShields"},{"id":1,"name":"AnnaRosales"},{"id":2,"name":"GravesBryant"}],"greeting":"Hello,MasseySaunders!Youhave8unreadmessages.","favoriteFruit":"apple"}
------------------------------------------------------------
~/projects » python3 -m json.tool test.json
{
"_id": "5f12d319624e57e27d1291fe",
"index": 0,
"name": "MasseySaunders",
"gender": "male",
"company": "TALAE",
"email": "masseysaunders@talae.com",
"phone": "+1(853)508-3237",
"address": "246IndianaPlace,Glenbrook,Iowa,3896",
"registered": "2017-02-06T06:42:20-08:00",
"latitude": -10.269827,
"longitude": -103.12419,
"friends": [
{
"id": 0,
"name": "DorotheaShields"
},
{
"id": 1,
"name": "AnnaRosales"
},
{
"id": 2,
"name": "GravesBryant"
}
],
"greeting": "Hello,MasseySaunders!Youhave8unreadmessages.",
"favoriteFruit": "apple"
}
搭建http服务器¶
打开py文档¶
~/projects » python3 -m pydoc -p 8002
Server ready at http://localhost:8002/
Server commands: [b]rowser, [q]uit
server>
直接进入pdb¶
~/projects » python3 -m pdb test.py
> /Users/hejl/projects/test.py(1)<module>()
-> print("hello")
(Pdb)