python基础¶

字典dict¶

字典排序¶

name = ['达拉斯', '大幅', '热个', '个胡', '圣啊']
age = [31, 32, 33, 34, 35]
index = [5, 2, 3, 4, 1]
diclist = []
for i in range(len(name)):
    dic = {'name': name[i], 'age': age[i], 'index': index[i]}
    diclist.append(dic)
# 字典排序
c = sorted(diclist, key=lambda diclist: diclist['index'], reverse=False)
print(c)

列表list¶

列表生成¶

lis = [i for i in range(5)]
print(lis)

列表切片¶

a = ["one", "two", "3", 4, 5]
b = a[0:3]  # 简单切片
print(b)
c = a[0:3:1]  # 带步长
print(c)
d = a[::-1]  # 相当于反转列表
print(d)

列表排序¶

a = ["第一","第二","第三","第四","第五","第六"]
# 获得列表排序序号
b = np.argsort(a)
c = a.sort()
d = a.sort(reverse=True)  # sort 不产生新的list

newlist1 = sorted(a)  # sorted产生一个新的list
newlist2 = sorted(a, reverse=True)

时间和日期time and date¶

导入库¶

import datetime
import time
import pyodbc

# 数据库中的日期可以直接加.strftime("%Y-%m-%d %X")转成字符串

时间戳¶

# 时间戳 1640136459.9968226
timestamp = time.time()
print('时间戳:', timestamp)

结构化时间¶

# 结构化时间time.struct_time(tm_year=2021, tm_mon=12, tm_mday=22, tm_hour=9, tm_min=27, tm_sec=39, tm_wday=2, tm_yday=356, tm_isdst=0)
st = time.localtime()
print(st)
"""
属性                            值
tm_year（年）                  比如2011 
tm_mon（月）                   1 - 12
tm_mday（日）                  1 - 31
tm_hour（时）                  0 - 23
tm_min（分）                   0 - 59
tm_sec（秒）                   0 - 61
tm_wday（weekday）             0 - 6（0表示周日）
tm_yday（一年中的第几天）        1 - 366
tm_isdst（是否是夏令时）        默认为-1
"""

结构时间转时间戳¶

# 结构时间转时间戳
ts_st = time.mktime(time.localtime())
print(ts_st)

时间戳转结构时间¶

# 时间戳转结构时间1640115563.0710912
print(time.localtime(1640115563.0710912))

# 间戳转日期
s = time.time()
print(s)
a = datetime.date.fromtimestamp(s)
print(a, type(a))
b = a.timetuple()  # 返回日期对应的time.struct_time对象；通过这个把datetime.date转成time.struct_time
print(b)
c = time.mktime(b)  # 然后又可以转回时间戳
print(c)
# 此时的c跟最初的s比，已经失去了时间信息

# 这时候可以把a的结构时间转成格式化时间
d = a.strftime("%Y%m%d")  # 把datetime.date格式转化成需要的字符串格式
print(d)


# 时间戳转日期时间
# 根据时间戳创建datetime对象 2021-12-22 10:27:29.141444 <class 'datetime.datetime'>
a = datetime.datetime.fromtimestamp(time.time())
print(a, type(a))

格式化时间转结构时间¶

# 格式化时间转结构时间
a = time.strptime('2011-05-05 16:37:06', '%Y-%m-%d %X')
print(a, type(a))
# time.struct_time(tm_year=2011, tm_mon=5, tm_mday=5, tm_hour=16,
# tm_min=37, tm_sec=6, tm_wday=3, tm_yday=125, tm_isdst=-1) <class 'time.struct_time'>
b = datetime.datetime.strptime('2011-05-05 16:37:06', '%Y-%m-%d %X')
print(b, type(b))
# 2011-05-05 16:37:06 <class 'datetime.datetime'>

结构时间转格式化时间¶

# 结构时间转格式时间
a1 = time.strftime("%Y-%m-%d %X")
a2 = time.strftime("%x %X")
time.strftime("%Y-%m-%d %X", time.localtime())
print(a1)  # 2021-12-22 09:54:52
print(a2)  # 12/22/21 09:54:52


# 把datetime.datetime转成想要的字符串格式
a = datetime.datetime.now().strftime("%Y-%m-%d %X")
print(a, type(a))

其他时间样式¶

# 其他时间样式 Wed Dec 22 09:49:39 2021 <class 'str'>
d = time.asctime(time.localtime())
c = time.ctime(time.time())
print(d, type(d))
print(c, type(c))
# c 和 d 都是字符串

计时¶

# 计时和延迟，延时，delay，睡眠
start = time.time()
time.sleep(0.1)
elapsed = (time.time() - start)
print("用时:", elapsed)

日期¶

# 获取今天日期 2021-12-22 <class 'datetime.date'>
jtrq = datetime.date.today()
print(jtrq, type(jtrq))
# 2021-12-22 <class 'str'>
strjtrq = str(jtrq)
print(strjtrq, type(strjtrq))

日期时间¶

a = datetime.datetime.today()
print(a, type(a))  # 2021-12-22 10:28:48.867435 <class 'datetime.datetime'>
b = datetime.datetime.now()
print(b, type(b))  # 2021-12-22 10:28:48.867435 <class 'datetime.datetime'>
# a和b是一样的

# 获取数据库需要的日期时间datetime格式的日期date
today = datetime.datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)

日期偏移¶

# datetime的日期偏移
# timedelta类 日期加减 日期偏移
dt1 = datetime.datetime.now() + datetime.timedelta(days=-1)  # 昨天
dt2 = datetime.datetime.now() - datetime.timedelta(days=1)  # 昨天
dt3 = datetime.datetime.now() + datetime.timedelta(days=1)  # 明天
print(dt1, dt2, dt3)


# 基于数据库数据的日期偏移
def dateoffset(mydate, offsetday, offsettype):
    cnxn = pyodbc.connect(xztApp_data_mssql_pyodbc_xtool)
    cursor = cnxn.cursor()
    cursor.execute("""select * from t_general_tradedate ORDER BY date DESC""")
    myfetch = cursor.fetchall()
    cursor.close()
    cnxn.close()
    listlen = len(myfetch)
    if mydate > myfetch[0][0].strftime("%Y%m%d") or mydate < myfetch[listlen - 1][0].strftime("%Y%m%d"):
        return '日期超出范围'

    for dayi in range(listlen):
        if myfetch[dayi][0].strftime("%Y%m%d") == mydate:
            nowdayindex = dayi
            break
    mycount = 0
    if offsetday > 0:
        if offsettype == 1:
            for dayi in range(1, listlen):
                if nowdayindex - dayi < 0:
                    return '日期超出范围'
                else:
                    if myfetch[nowdayindex - dayi][2] == 1:
                        mycount = mycount + 1
                    if mycount == abs(offsetday):
                        return myfetch[nowdayindex - dayi][0].strftime("%Y%m%d")
        else:
            if nowdayindex + offsetday < 0:
                return '日期超出范围'
            else:
                return myfetch[nowdayindex - offsetday][0].strftime("%Y%m%d")
    elif offsetday < 0:
        if offsettype == 1:
            for dayi in range(1, listlen):
                if nowdayindex + dayi > listlen - 1:
                    return '日期超出范围'
                else:
                    if myfetch[nowdayindex + dayi][2] == 1:
                        mycount = mycount + 1
                        if mycount == abs(offsetday):
                            return myfetch[nowdayindex + dayi][0].strftime("%Y%m%d")
                    else:
                        continue
        else:
            if nowdayindex + offsetday > listlen - 1:
                return '日期超出范围'
            else:
                return myfetch[nowdayindex - offsetday][0].strftime("%Y%m%d")
    elif offsetday == 0:
        return myfetch[nowdayindex][0].strftime("%Y%m%d")

周几¶

def get_week_day(date):
    week_day_dict = {
        0: '星期一',
        1: '星期二',
        2: '星期三',
        3: '星期四',
        4: '星期五',
        5: '星期六',
        6: '星期天',
    }
    day = date.weekday()
    return week_day_dict[day]

a = get_week_day(datetime.datetime.now())
print(a)

虚拟环境¶

# 切换
# cd C:\Python36


# 创建虚拟
# python -m venv myenv


# 激活虚拟环境
# .\myenv\Scripts\activate

# 可以安装Flask
# pip install Flask

# 停止
# deactivate