TIME

GMT时间格式

1GMT_FORMAT = '%a, %d %b %Y %H:%M:%S GMT'

获取某个时间的时间戳

1import datetime
2import time
3
4string = "2018-03-31"
5date_time = datetime.datetime.strptime(string, '%Y-%m-%d')
6time_time = time.mktime(date_time.timetuple())
7print(time_time)

得到当天0点时间

1today = datetime.datetime.today()
2b = datetime.datetime(today.year, today.month, today.day, 0, 0, 0)
3print(b)
4
5now = time.time()
6midnight = now - (now % 86400) + time.timezone
7itime = time.ctime(midnight)
8print(itime)

时间或时间戳与字符串转换

 1#把datetime转成字符串
 2def datetime_toString(dt):
 3    return dt.strftime("%Y-%m-%d-%H")
 4
 5#把字符串转成datetime
 6def string_toDatetime(string):
 7    return datetime.strptime(string, "%Y-%m-%d-%H")
 8
 9#把字符串转成时间戳形式
10def string_toTimestamp(strTime):
11    return time.mktime(string_toDatetime(strTime).timetuple())
12
13#把时间戳转成字符串形式
14def timestamp_toString(stamp):
15    return time.strftime("%Y-%m-%d-%H", time.localtime(stamp))
16
17#把时间戳转成datetime
18def timestamp_toDatetime(stamp):
19    return datetime.fromtimestamp(stamp)
20
21#把datetime类型转外时间戳形式
22def datetime_toTimestamp(dateTim):
23    return time.mktime(dateTim.timetuple())

秒转化为时分秒

1def time_string(seconds):
2    hours, _minutes = divmod(seconds, 3600)
3    minutes, seconds = divmod(_minutes, 60)
4    return (hours, minutes, seconds)

获取上个月开始与结束时间

 1from datetime import datetime, timedelta
 2
 3
 4def gen_zero_time():
 5    '''
 6    生成当天零点时间
 7    '''
 8    today = datetime.today()
 9    b = datetime(today.year, today.month, today.day, 0, 0, 0)
10    return b
11
12
13d = gen_zero_time()
14end_date = d.replace(day=1)
15start_date = (d.replace(day=1) + timedelta(days=-1)).replace(day=1)
16print(start_date)
17print(end_date)

获取上周星期天与星期六

1from datetime import datetime, timedelta
2from dateutil import relativedelta
3today = datetime.now()
4start = today - timedelta((today.weekday() + 1) % 7)
5sat = start + relativedelta.relativedelta(weekday=relativedelta.SA(-1))
6sun = sat + relativedelta.relativedelta(weekday=relativedelta.SU(-1))
7print(sat)
8print(sun)

获取上周时间(星期天零点到星期天零点)

 1from datetime import datetime, timedelta
 2
 3
 4def gen_zero_time():
 5    '''
 6    生成当天零点时间
 7    '''
 8    today = datetime.today()
 9    b = datetime(today.year, today.month, today.day, 0, 0, 0)
10    return b
11
12
13a = gen_zero_time()
14start_date = a + timedelta(days=-a.weekday() - 1, weeks=-1)
15end_date = start_date + timedelta(days=7)
16print(start_date)
17print(end_date)

HTTP

在网址中加入参数

 1import urllib
 2import urlparse
 3
 4
 5def url_add_params(url, **params):
 6    """ 在网址中加入新参数 """
 7    pr = urlparse.urlparse(url)
 8    query = dict(urlparse.parse_qsl(pr.query))
 9    query.update(params)
10    prlist = list(pr)
11    prlist[4] = urllib.urlencode(query)
12    return urlparse.ParseResult(*prlist).geturl()
13
14
15if __name__ == "__main__":
16    url = 'http://bbs.163.com'
17    print url_add_params(url, token=123, site="bbs")

urllib2发送json数据 POST请求

 1import json
 2import urllib2
 3
 4data = {
 5        'ids': [12, 3, 4, 5, 6]
 6}
 7
 8req = urllib2.Request('http://example.com/api/posts/create')
 9req.add_header('Content-Type', 'application/json')
10
11response = urllib2.urlopen(req, json.dumps(data))

urllib2发送PUT或DELETE请求

 1import urllib2
 2opener = urllib2.build_opener(urllib2.HTTPHandler)
 3request = urllib2.Request('http://example.org', data='your_put_data')
 4request.add_header('Content-Type', 'your/contenttype')
 5request.get_method = lambda: 'PUT'
 6url = opener.open(request)
 7
 8# 或者使用httplib
 9import httplib
10conn = httplib.HTTPConnection('www.foo.com')
11conn.request('PUT', '/myurl', body)
12resp = conn.getresponse()
13content = resp.read()

Syntax

解析赋值字符串

即把

1a=b c=d e=f g.a=1 g.a.b=2 g.c.d=3 h="a b c" i='sss'

解析成

1{'a': 'b', 'c': 'd', 'e': 'f', 'g': {'a': {'b': '2'}, 'c': {'d': '3'}}, 'h': 'a b c', 'i': 'sss'}

 1regex = re.compile(r"([\w.]+|\"[^=]*|'[^=]*)=(\"[^\"]*\"|'[^']*'|.*?)(\s|$)")
 2
 3def parse_string(string):
 4    r = {}
 5
 6    def _get(key):
 7        key = key.strip()
 8        if key[0] == key[-1] in ["'", "\""]:
 9            return key[1:-1]
10        return key
11
12    def _update(value, nvalue):
13        if not isinstance(nvalue, dict) or not isinstance(value, dict):
14            return nvalue
15        for k, v in nvalue.items():
16            value.setdefault(k, dict())
17            if isinstance(v, dict):
18                v = _update(value[k], v)
19            value[k] = v
20        return value
21
22    def _set(key, value):
23        for i in key.split(".")[::-1]:
24            value = {i: value}
25        return value
26
27    for key, value in regex.findall(string):
28        r = _update(r, _set(_get(key), _get(value)))
29    return r

字典递归更新

即当更新dict的value也是一个dict时，递归更新相应内容

1def update(value, nvalue):
2    if not isinstance(nvalue, dict) or not isinstance(value, dict):
3        return nvalue
4    for k, v in nvalue.items():
5        if isinstance(v, dict):
6            v = update(value[k], v)
7        value.update({k: v})
8    return value

字典使用dot

 1class dotdict(dict):
 2
 3    __setattr__ = dict.__setitem__
 4    __delattr__ = dict.__delitem__
 5
 6    def __getattr__(self, name):
 7        value = self[name]
 8        if isinstance(value, dict):
 9            return dotdict(value)
10        return value
11
12
13a = {'a': 1, 'b': 2, 'c': 3, 'd': {'a': '1', '1': 1}}
14c = dotdict(a)
15print(c.a)
16print(c.d.a)

或者

1class dotdict(object):
2    def __init__(self, **kwargs):
3        for key, value in kwargs.items():
4            setattr(self, key, value)

单例模式

 1from functools import wraps
 2from threading import Lock
 3
 4
 5def singleton(class_):
 6    instances = {}
 7    _lock = Lock()
 8
 9    @wraps(class_)
10    def _instance(*args, **kwargs):
11        with _lock:
12            if class_ not in instances:
13                instances[class_] = class_(*args, **kwargs)
14            instances[class_].__init__(*args, **kwargs)
15        return instances[class_]
16
17    return _instance
18
19@singleton
20class AA(object):
21    def __init__(self, a):
22        self.a = a
23
24    def aa(self):
25        print(self.a)
26
27
28a = AA('ccc').aa()
29b = AA('baabb').aa()
30print(id(a) == id(b))

Pip

pip更新所有的packages

1pip freeze --local | grep -v '^\-e' | cut -d = -f 1  | xargs -n1 pip install -U

如果是更新sudo安装的packages

1pip freeze --local | grep -v '^\-e' | cut -d = -f 1  | xargs -n1 sudo pip install -U

pip指定国内源

1pip install flask_migrate -i http://mirrors.aliyun.com/pypi/simple/ --trusted-host mirrors.aliyun.com

判斷是否激活virtualenv

1import sys
2if hasattr(sys, 'real_prefix'):
3   return True

Django model得到所有field name

1MyModel._meta.get_all_field_names()

python运行超时设置

 1import signal
 2
 3class TimeoutError(Exception):
 4    pass
 5
 6def timeout(seconds=10, error_message="Timer expired"):
 7    def _timeout(func):
 8        def _handle_timeout(signum, frame):
 9            raise TimeoutError(error_message)
10
11        def wrapper(*args, **kwargs):
12            signal.signal(signal.SIGALRM, _handle_timeout)
13            signal.alarm(seconds)
14            try:
15                result = func(*args, **kwargs)
16            finally:
17                signal.alarm(0)
18            return result
19
20        return wrapper
21
22    return _timeout

库

json.loads时无法保持字典列表的顺序

https://stackoverflow.com/questions/47111058/json-loads-doesnt-keep-order

1from json import loads
2from collections import OrderedDict
3loads(your_json_string, object_pairs_hook=OrderedDict)

http://www.grokcode.com/864/snakefooding-python-code-for-complexity-visualization/

其它

获取文件最后n行数据

 1import mmap
 2
 3
 4def getlastline(fname, n=1):
 5    with open(fname) as source:
 6        mapping = mmap.mmap(source.fileno(), 0, prot=mmap.PROT_READ)
 7    cursor = -1
 8    while n > 0:
 9        n -= 1
10        cursor = mapping.rfind(b'\n', 0, cursor)
11    return mapping[cursor:].decode().split("\n")

python列表中去除烦人的"u"

1# !/usr/bin/env python2
2# -*- coding: utf-8 -*-
3
4s = [u"python", u"golang", u"lua"]
5print(s)

• python script

  1s = [u"python", u"golang", u"lua"]
  2print([str(i) for i in s])

• jinja2

  1from jinja2 import Template
  2template = Template(
  3    '[{% for i in consul_join %}"{{ i | string }}"{% if not loop.last %},{% endif %}{% endfor %}]'
  4)
  5template.render(consul_join=[u"python", u"golang", u"lua"])

常见问题

PROTOCOL_SSLv3 is not defined

https://github.com/docker-library/python/issues/29

1bash -c 'sed -i s/PROTOCOL_SSLv3/PROTOCOL_SSLv23/g /usr/local/lib/python2.7/site-packages/gevent/ssl.py && python prober.py'