# python 实训总结Ⅰ

## 6.17

 1  print("Hello World!") 

  1 2 3 4 5 6 7 8 9 10  class zxm(): def __init__(self): self.x=0 self.y=0 def move_up(self): self.y +=1 my_zxm=zxm() print(my_zxm) 
 1  <__main__.zxm object at 0x000001D99CFEF668> 

## 6.18

### 输入输出

print 输出
input 输入
eval 执行一个字符串表达式，并返回表达式的值

 1 2 3 4  x=eval(input("请输入x的值：")) y=eval(input("请输入y的值：")) z=(x**2+y**2)**0.5 print(z) 
 1 2 3 4 5 6  # 导入复数数学模块 import cmath num = int(input("请输入一个数字: ")) num_sqrt = cmath.sqrt(num) print('{0} 的平方根为 {1:0.3f}+{2:0.3f}j'.format(num ,num_sqrt.real,num_sqrt.imag)) 

### 数据类型

• 字符串： "" ''
• 元组tuple(2,3)
• 列表list[2,3]
• 字典dict{Key:Value}
• 集合{}
 1 2  x=[1,10] type(x)#判断元素类型 
 1  list 

### 循环判断

 1 2  for x in range(1,10,2): # (start,stop,step) pass # pass不做任何事情，一般用做占位语句 
 1 2 3 4 5 6 7  for letter in 'Python': if letter == 'h': pass print('这是 pass 块') print('当前字母 :'+ letter) print("Good bye!") 
 1 2 3 4 5 6 7 8  当前字母 :P 当前字母 :y 当前字母 :t 这是 pass 块 当前字母 :h 当前字母 :o 当前字母 :n Good bye! 

### str() 、 import导库

 1 2  x=10 print("整数转字符串"+str(x)) 
 1  import this 
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21  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!