Python3（三）

# 包
# 点模块名称
# A.B 表示包A中的子模块B
# 几种导包方式

import sound.effects.echo;

form sound.effects import echo;

form sound.effects import *;

###########################

s = ‘erbaohuadou‘;
print(s); # erbaohuadou
print(repr(s)); # ‘erbaohuadou‘
print(str(1/7)); # 0.14285714285714285
print(1/7); # 0.14285714285714285

x = 5 * 3.25;
y = 200 * 200;

s = ‘The value of x: ‘ + repr(x) + ‘the value of y: ‘ + repr(y)

print(s); # The value of x: 16.25the value of y: 40000

print(‘狗狗的名字{}二宝的名字{}‘.format(‘huadou‘, ‘erbao‘)); # 狗狗的名字huadou二宝的名字erbao
print(‘狗狗的名字{1}二宝的名字{0}‘.format(‘erbao‘, ‘huadou‘)); # 狗狗的名字huadou二宝的名字erbao
print(‘狗狗的名字{dogName}二宝的名字{rabName}‘.format(rabName=‘erbao‘, dogName=‘huadou‘)); # 狗狗的名

字huadou二宝的名字erbao

import math;
print(‘圆周率值：{}‘.format(math.pi)); # 圆周率值：3.141592653589793
print(‘圆周率值：{!r}‘.format(math.pi)); # 圆周率值：3.141592653589793
print(‘圆周率值：{0:.3f}‘.format(math.pi)); # 圆周率值：3.142

# 格式化数字、表格
table = {‘item1‘: 4578, ‘item2‘: 7244, ‘item3‘: 2344};

for name,phone in table.items():
    print(‘{0:10}==>{1:10d}‘.format(name, phone));


# 读写文件
f = open(‘test.txt‘, ‘r+‘);
print(f.read());
# print(f.write(‘this is a text.‘)); # 15
print(f.tell()); # 118
print(f.close()); # None