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Python day1-20

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Python notes day 1

1.Run python: python name.py

2.Comment:

“””

multiple line

“””

  1. Sublime Text or PyCharm for python ide.

  2. import this#put this in terminal, the zen of python

    The Zen of Python, by Tim Peters

Beautiful is better than ugly.

Explicit is better than implicit.

Simple is better than complex.

Complex is better than complicated.

Flat is better than nested.

Sparse is better than dense.

Readability counts.

Special cases aren’t special enough to break the rules.

Although practicality beats purity.

Errors should never pass silently.

Unless explicitly silenced.

In the face of ambiguity, refuse the temptation to guess.

There should be one– and preferably only one –obvious way to do it.

Although that way may not be obvious at first unless you’re Dutch.

Now is better than never.

Although never is often better than right now.

If the implementation is hard to explain, it’s a bad idea.

If the implementation is easy to explain, it may be a good idea.

Namespaces are one honking great idea – let’s do more of those!

Python notes day 2

  1. True, False, None

  2. Variable name: number, letter, _, and cannot use number as front.

  3. field instance, protected use , private use _

  4. type() : return <class ‘type’>

  5. chr(): int to unicode’s char

  6. ord(): unicode char to an int

  7. input(): for user input

  8. print(): for output

  9. %d是整数的占位符，%f是小数的占位符，%%表示百分号（因为百分号代表了占位符，所以带占位符的字符串中要表示百分号必须写成%%），字符串之后的%后面跟的变量值会替换掉占位符然后输出到终端中

  10. 运算符 描述
    [] [:] 下标，切片
    ** 指数
    ~ + - 按位取反, 正负号
    * / % // 乘，除，模，整除
    + - 加，减
    >> << 右移，左移
    & 按位与
    ^ ` `
    <= < > >= 小于等于，小于，大于，大于等于
    == != 等于，不等于
    is is not 身份运算符
    in not in 成员运算符
    not or and 逻辑运算符

    and, or , not

  11. 在使用print函数输出时，也可以对字符串内容进行格式化处理，上面print函数中的字符串%1.f是一个占位符，稍后会由一个float类型的变量值替换掉它。同理，如果字符串中有%d，后面可以用一个int类型的变量值替换掉它，而%s会被字符串的值替换掉。除了这种格式化字符串的方式外，还可以用下面的方式来格式化字符串，其中{f:.1f}和{c:.1f}可以先看成是{f}和{c}，表示输出时会用变量f和变量c的值替换掉这两个占位符，后面的:.1f表示这是一个浮点数，小数点后保留1位有效数字。

  12. print(f'{f:.1f}华氏度 = {c:.1f}摄氏度')

    1
    2
    3

    13. ```python
        print('面积: %.2f' % area)

  13. python print格式化输出。

    1. 打印字符串
    1
    print ("His name is %s"%("Aviad"))

    效果：
    img

    2.打印整数

    1
    print ("He is %d years old"%(25))

    效果：
    img

    3.打印浮点数

    1
    print ("His height is %f m"%(1.83))

    效果：
    img

    4.打印浮点数（指定保留小数点位数）

    1
    print ("His height is %.2f m"%(1.83))

    效果：
    img

    5.指定占位符宽度

    1
    print ("Name:%10s Age:%8d Height:%8.2f"%("Aviad",25,1.83))

    效果：
    img

    6.指定占位符宽度（左对齐）

    1
    print ("Name:%-10s Age:%-8d Height:%-8.2f"%("Aviad",25,1.83))

    效果：
    img

    7.指定占位符（只能用0当占位符？）

    1
    print ("Name:%-10s Age:%08d Height:%08.2f"%("Aviad",25,1.83))

    效果：
    img

    8.科学计数法

    1
    format(0.0015,'.2e')

    效果：

    img

Python notes day 3

1.if, elif, else

Python notes day 4

  1. for in 循环： for x in range(a, b, c):# a是初始值，b是最终，到b-1, c是iterate的长度。
  2. while循环，配上break，continue

Python notes day 5

CRAPS game:

非常好玩的游戏， 在桌面新建.py结尾的文件或用idle直接打开即可

注意： python2可能不支持中文

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from random import randint

money = 1000
while money > 0:
    print('你的总资产为:', money)
    needs_go_on = False
    while True:
        debt = int(input('请下注: '))
        if 0 < debt <= money:
            break
    first = randint(1, 6) + randint(1, 6)
    print('玩家摇出了%d点' % first)
    if first == 7 or first == 11:
        print('玩家胜!')
        money += debt
    elif first == 2 or first == 3 or first == 12:
        print('庄家胜!')
        money -= debt
    else:
        needs_go_on = True
    while needs_go_on:
        needs_go_on = False
        current = randint(1, 6) + randint(1, 6)
        print('玩家摇出了%d点' % current)
        if current == 7:
            print('庄家胜')
            money -= debt
        elif current == first:
            print('玩家胜')
            money += debt
        else:
            needs_go_on = True
print('你破产了, 游戏结束!')