Python学习笔记
查看当前路径
import os,sys
#获取工作路径（即操作的pwd）
print(os.getcwd())
#获取脚本路径
print(sys.path[0])
# 查看相关数据
print('__file__={0:<35} | __name__={1:<20} | __package__={2:<20}'.format(__file__,__name__,str(__package__)))
路径跳转
#!/usr/bin/python
import os,sys
print __file__
print os.path.realpath(__file__)
print os.path.dirname(os.path.realpath(__file__))
sys.path.append(os.path.dirname(os.path.realpath(__file__)))
os.chdir("../")
path = "C://"
# Check current working directory.
retval = os.getcwd()
print "Current working directory %s" %retval
# Now change the directory
os.chdir( path )
# Check current working directory.
retval = os.getcwd()
print "Directory changed successfully %s" %retval
#结果：
C:\Users\Administrator\Desktop\55kai>py -2 findme.py
findme.py
C:\Users\Administrator\Desktop\55kai\findme.py
C:\Users\Administrator\Desktop\55kai
Current working directory C:\Users\Administrator\Desktop
Directory changed successfully C:\
搜索文件
import os
import sys
count = 0
def search(dstDir,fileName):
global count
#files = [os.path.join(dstDir,x) for x in os.listdir(dstDir)]
for files in os.listdir(dstDir):
absPath = os.path.join(dstDir,files)
if os.path.isdir(absPath):
try:
search(absPath,fileName)
except Exception as e:
continue
elif (os.path.isfile(absPath) and os.path.split(absPath)[1].lower()==fileName.lower()):
count +=1
print(absPath)
search(sys.path[0],"file.py")
print("%d founded"%count)
动态加载模块
#加载模块
__import__(modules_file)
#指定模块
tmp = sys.modules[modules_file]
#模块函数调用
tmp.use(target)
修改文件内容
def alter(file,old_str,new_str):
"""
替换文件中的字符串
:param file:文件名
:param old_str:就字符串
:param new_str:新字符串
:return:
"""
file_data = ""
with open(file, "r", encoding="utf-8") as f:
for line in f:
if old_str in line:
line = line.replace(old_str,new_str)
file_data += line
with open(file,"w",encoding="utf-8") as f:
f.write(file_data)
alter("file1", "09876", "python")
遍历所有文件
import sys
import os
def get_files(path, rule):
all_files = []
for fpath, dirname, fnames in os.walk(path): # os.walk是获取所有的目录
for filename in fnames:
path_name = os.path.join(fpath,filename)
if path_name.endswith(rule): # 判断是否是"xxx"结尾
all_files.append(path_name)
return all_files
def main():
all_files = get_files(sys.path[0],".py")
for filename in all_files:
print(filename)
if __name__ == "__main__":
main()
with open()
https://www.cnblogs.com/ymjyqsx/p/6554817.html
with open('/path/to/file', 'r') as f:
print(f.read())
for line in f.readlines():
print(line.strip()) # 把末尾的'\n'删掉
r 只能读
r+ 可读可写，不会创建不存在的文件。如果直接写文件，则从顶部开始写，覆盖之前此位置的内容，如果先读后写，则会在文件最后追加内容。
w+ 可读可写 如果文件存在 则覆盖整个文件不存在则创建
w 只能写 覆盖整个文件 不存在则创建
a 只能写 从文件底部添加内容 不存在则创建
a+ 可读可写 从文件顶部读取内容 从文件底部添加内容 不存在则创建
python2转python3
#2to3.py位于python2.7\Tools\Scripts
#将python2脚本E:\\python2script\\全部转为python3
python2 2to3.py -w E:\\python2script\\
python3与python2兼容性问题
使用popen以系统命令的形式去运行python2脚本
import载入相对路径模块
start.py
app/
__init__.py
sub1/
__init__.py
mod1.py
sub2/
__init__.py
mod2.py
1、起点要高，从app同级的start开始。
2、mod1.py中from ..sub2 import mod2.py
资料：
https://www.napuzba.com/story/import-error-relative-no-parent/
toplevel
├── main.py
└── project
├── __init__.py
├── config.py
└── package
├── __init__.py
└── demo.py
import ..
import .
print('__file__={0:<35} | __name__={1:<20} | __package__={2:<20}'.format(__file__,__name__,str(__package__)))W
Web API
Flask
http://www.pythondoc.com/flask/quickstart.html#id2
@app.route('/')
def index():
return 'Index Page'
@app.route('/hello')
def hello():
return 'Hello World'
@classmethod与@staticmethod
#实现：
#实现仅仅与类交互而不是和实例交互的方法
#并且不要扩散类内部的代码，造成维护困难。
class Kls(object): #类
no_inst = 0
def __init__(self):
Kls.no_inst = Kls.no_inst + 1
#@classmethod装饰器来创建类方法。不管这个方式是从实例调用还是从类调用，它都用第一个参数把类传递过来。
@classmethod
def get_no_of_instance(cls_obj):
return cls_obj.no_inst
ik1 = Kls()
ik2 = Kls()
print ik1.get_no_of_instance()
print Kls.get_no_of_instance()
ik1 = Kls()
print ik1.get_no_of_instance()
print Kls.get_no_of_instance()
ik2 = Kls()
print ik1.get_no_of_instance()
print Kls.get_no_of_instance()
#每一次实例化类，都会执行一次。
#@staticmethod只要放不会变化的内容
class Kls2(object):
def __init__(self, data):
self.data = data
def printd(self):
print(self.data)
@staticmethod
def smethod(*arg):
print('Static:', arg)
@classmethod
def cmethod(*arg):
print('Class:', arg)
pip3
python3 -m pip install -r requirement.txt
FIX
1、缺少gcc依赖环境
报错提示：
gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong –param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong –param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I/usr/include/python2.7 -c psutil/_psutil_linux.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_linux.o
unable to execute gcc: No such file or directory
error: command ‘gcc’ failed with exit status
解决： yum -y install gcc
2、缺少python-dev依赖环境
报错提示： psutil/_psutil_linux.c:12:20: fatal error: Python.h: No such file or directory
#include
解决： yum -y install python-devel.x86_64
在centos下，并且是python3的时候，用：
yum install python34-devel
3、win下缺少djcelery
ModuleNotFoundError: No module named 'djcelery'
实际模块名是django-celery
所以要用pip install django-celery
sqlite3
import sqlite3
con = sqlite3.connect("mydb")
con.row_factory = sqlite3.Row
cur = con.cursor()
cur.execute("select name_last, age from people")
for row in cur:
assert row[0] == row["name_last"]
assert row["name_last"] == row["nAmE_lAsT"]
assert row[1] == row["age"]
assert row[1] == row["AgE"]
遍历字典和数组
#查找Success是否为true
def list_all_dict(dict_a):
global Success
if isinstance(dict_a, dict): # 使用isinstance检测数据类型
for x in range(len(dict_a)):
temp_key = list(dict_a.keys())[x]
temp_value = dict_a[temp_key]
print("%s : %s" % (temp_key, temp_value))
list_all_dict(temp_value) # 自我调用实现无限遍历
elif isinstance(dict_a, list):
for x in range(len(dict_a)):
temp_value = dict_a[x]
print("%s" % (temp_value))
list_all_dict(temp_value) # 自我调用实现无限遍历
pycharm 调试gevent
在Settings->Python Debugger->Gevent compatible打上勾。
（— _— 哭了，一开始不知道，盲调多线程）
django开发
FIX
1、ImportError: cannot import name ‘TEMPLATE_CONTEXT_PROCESSORS’
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "E:\1_Setup\17_python3.6.2\lib\site-packages\django\core\management\__init__.py", line 371, in execute_from_command_line
utility.execute()
File "E:\1_Setup\17_python3.6.2\lib\site-packages\django\core\management\__init__.py", line 317, in execute
settings.INSTALLED_APPS
File "E:\1_Setup\17_python3.6.2\lib\site-packages\django\conf\__init__.py", line 56, in __getattr__
self._setup(name)
File "E:\1_Setup\17_python3.6.2\lib\site-packages\django\conf\__init__.py", line 43, in _setup
self._wrapped = Settings(settings_module)
File "E:\1_Setup\17_python3.6.2\lib\site-packages\django\conf\__init__.py", line 106, in __init__
mod = importlib.import_module(self.SETTINGS_MODULE)
File "E:\1_Setup\17_python3.6.2\lib\importlib\__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 978, in _gcd_import
File "<frozen importlib._bootstrap>", line 961, in _find_and_load
File "<frozen importlib._bootstrap>", line 950, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 655, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 205, in _call_with_frames_removed
File "G:\11_Thinking\3_PocScan\4_MuheScanner\pocscan-master\pocscanui\settings.py", line 72, in <module>
from django.conf.global_settings import TEMPLATE_CONTEXT_PROCESSORS as TCP
ImportError: cannot import name 'TEMPLATE_CONTEXT_PROCESSORS'
解决：
Remove this line from your settings:
from django.conf.global_settings import TEMPLATE_CONTEXT_PROCESSORS as TCP
TEMPLATE_CONTEXT_PROCESSORS was deprecated in Django 1.8 and removed in Django 1.10. It’s not possible to import it anymore.
You have already defined context_processors in your TEMPLATES setting, so you don’t need TEMPLATE_CONTEXT_PROCESSORS anymore.
虚拟环境
mkvirtualenv zqxt：创建运行环境zqxt
workon zqxt: 工作在 zqxt 环境 或 从其它环境切换到 zqxt 环境
deactivate: 退出终端环境
其它的：
rmvirtualenv ENV：删除运行环境ENV
mkproject mic：创建mic项目和运行环境mic
mktmpenv：创建临时运行环境
lsvirtualenv: 列出可用的运行环境
lssitepackages: 列出当前环境安装了的包
创建的环境是独立的，互不干扰，无需sudo权限即可使用 pip 来进行包的管理。
subprocess：子程序调用
http://blog.csdn.net/g457499940/article/details/17068277
subprocess.Popen.poll
0 正常结束
1 sleep
2 子进程不存在
-15 kill
None 在运行
self.proc.poll() is not None判断进行是否结束
多线程
http://chengable.com/index.php/archives/331/
SaltStack 配置gitfs报错yacc table file version is out of date
yum remove libgit2 python-pygit2
wget https://github.com/libgit2/libgit2/archive/v0.25.1.tar.gz
tar -zxf v0.25.1.tar.gz && cd libgit2-0.25.1/
mkdir build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DLIB_INSTALL_DIR=/lib64
cmake --build . --target install
pip install pygit2
systemctl restart salt-master