python 基础小练习

#装饰器小练习：既可以输入文本也可以不输入

# -*- coding: utf-8 -*-
import time, functools
def metric(text):
    if isinstance(text,str):
        def decorator(func):
            @functools.wraps(func)
            def wrapper(*args, **kw):
                 print('%s %s():' % (text, func.__name__))
                 return func(*args, **kw)
            return wrapper
        return decorator
    else:
        @functools.wraps(text)
        def wrapper(*args, **kw):
            print('%s():' % text.__name__)
            return text(*args, **kw)

        return wrapper

@metric('execute')
def fast(x, y):
    time.sleep(0.0012)
    return x + y;

@metric
def slow(x, y, z):
    time.sleep(0.1234)
    return x * y * z;

f = fast(11, 22)
s = slow(11, 22, 33)
if f != 33:
    print('测试失败!')
elif s != 7986:
    print('测试失败!')

#类和实例：实例只是类的一个例子
class Student(object):
    def __init__(self, name, score):
        self.name = name
        self.score = score

    def get_grade(self):
        if self.score >= 90:
            return 'A'
        elif self.score >= 60:
            return 'B'
        else:
            return 'C'
lisa = Student('Lisa', 99)
bart = Student('Bart', 59)
print(lisa.name, lisa.get_grade())
print(bart.name, bart.get_grade())

# 父类与子类：继承
class animal(object):
    def run(self):
        print('animal is running...')
class Timer(object):
    def run(self):
        print('Start...')
def run_twice(animal):
    animal.run()
    animal.run()
run_twice(Timer())

结果：Start...Start...

#测试切片：去除首尾的空格

def trim(s):
    t=len(s)
    w1=0
    w2=t
    while (w1<w2):
        if s[w1]==' ':
            w1=w1+1
        if s[w2-1]==' ':
            w2=w2-1
        if s[w1]!=' 'and s[w2-1]!=' ':
            break
    s=s[w1:w2]
    print('s=',s)
    return s

if trim('hello  ') != 'hello':
    print('测试失败!')
elif trim('  hello') != 'hello':
    print('测试失败!')
elif trim('  hello  ') != 'hello':
    print('测试失败!')
elif trim('  hello  world  ') != 'hello  world':
    print('测试失败!')
elif trim('') != '':
    print('测试失败!')
elif trim('    ') != '':
    print('测试失败!')
else:
    print('测试成功!')

结果：

s= hello
s= hello
s= hello
s= hello  world
s= 
s= 
测试成功!

#假设你获取了用户输入的日期和时间如2015-1-21 9:01:30，以及一个时区信息如UTC+5:00，均是str，请编写一个函数将其转换为timestamp：

import re
from bs4 import BeautifulSoup
import pprint
import os
from datetime import datetime,timezone,timedelta
def to_timestamp(dt_str,tz_str):
    cday=datetime.strptime(dt_str,'%Y-%m-%d %H:%M:%S')
    t=tz_str[3:5]
    UT=int(t)
    ca=re.split(r'[- :]',dt_str)
    timefinal=cday.replace(tzinfo=timezone(timedelta(hours=UT)))
    return timefinal.timestamp()
t1 = to_timestamp('2015-6-1 08:10:30', 'UTC+7:00')
assert t1 == 1433121030.0, t1


t2 = to_timestamp('2015-5-31 16:10:30', 'UTC-9:00')
assert t2 == 1433121030.0, t2


print('ok')

结果：ok