python入门教程 5-------- Conditionals & Control Flow
---- Conditionals & Control Flow
30 介绍Python利用有6种比较的方式 == , != , > , >= , < , <=
2 比较后的结果是True或者是False
3 练习
1 把bool_one的值设置为 17 < 118%100
2 把bool_two的值设置为 100 == 33*3 + 1
3 把bool_two的值设置为 19 <= 2**4
4 把bool_four的值设置为 -22 >= -18
5 把bool_five的值设置为 99 != 98+1
[python]
#Assign True or False as appropriate on the lines below!
bool_one = 17 < 118%100
bool_two = 100 == 33*3+1
bool_three = 19 <= 2**4
bool_four = -22 >= -18
bool_five = 99 != 98+1
31 介绍了比较的两边不只是数值，也可以是两个表达式
2 练习
1 把bool_one的值设置为 20 + -10*2 > 10%3%2
2 把bool_two的值设置为 (10+17)**2 == 3**6
3 把bool_two的值设置为 1**2**3 <= -(-(-1))
4 把bool_four的值设置为 40/20*4 >= -4**2
5 把bool_five的值设置为 100**0.5 != 6+4
[python]
# Assign True or False as appropriate on the lines below!
bool_one = 20+-10*2 > 10%3%2
bool_two = (10+17)**2 == 3**6
bool_three = 1**2**3 <= -(-(-1))
bool_four = 40/20*4 >= -4**2
bool_five = 100**0.5 != 6+4
32 介绍了Python里面还有一种数据类型是booleans，值为True或者是False
2 练习：根据题目的意思来设置右边的表达式
[python]
# Create comparative statements as appropriate on the lines below!
# Make me true!
bool_one = 1 <= 2
# Make me false!
bool_two = 1 > 2
# Make me true!
bool_three = 1 != 2
# Make me false!
bool_four = 2 > 2
# Make me true!
bool_five = 4 < 5
33 介绍了第一种连接符and的使用，只有and的两边都是True那么结果才能为True
2 练习
1 设置变量bool_one的值为False and False
2 设置变量bool_two的值为-(-(-(-2))) == -2 and 4 >= 16**0.5
3 设置变量bool_three的值为19%4 != 300/10/10 and False
4 设置变量bool_four的值为-(1**2) < 2**0 and 10%10 <= 20-10*2
5 设置变量bool_five的值为True and True
[python]
bool_one = False and False
bool_two = -(-(-(-2))) == -2 and 4 >= 16**0.5
bool_three = 19%4 != 300/10/10 and False
bool_four = -(1**2) < 2**0 and 10%10 <= 20-10*2
bool_five = True and True
34 介绍了第二种连接符or的使用，只要or的两边有一个True那么结果才能为True
2 练习
1 设置变量bool_one的值为2**3 == 108%100 or 'Cleese' == 'King Arthur'
2 设置变量bool_two的值为True or False
3 设置变量bool_three的值为100**0.5 >= 50 or False
4 设置变量bool_four的值为True or True
5 设置变量bool_five的值为1**100 == 100**1 or 3*2*1 != 3+2+1
[python]
bool_one = 2**3 == 108%100 or 'Cleese' == 'King Arthur'
bool_two = True or False
bool_three = 100**0.5 >= 50 or False
bool_four = True or True
bool_five = 1**100 == 100**1 or 3*2*1 != 3+2+1
35 介绍第三种连接符not , 如果是not True那么结果为False，not False结果为True
2 练习
1 设置变量bool_one的值为not True
2 设置变量bool_two的值为not 3**4 < 4**3
3 设置变量bool_three的值为not 10%3 <= 10%2
4 设置变量bool_four的值为not 3**2+4**2 != 5**2
5 设置变量bool_five的值为not not False
[python]
bool_one = not True
bool_two = not 3**4 < 4**3
bool_three = not 10%3 <= 10%2
bool_four = not 3**2+4**2 != 5**2
bool_five = not not False
36 介绍了由于表达式很多所以我们经常使用()来把一些表达式括起来，这样比较具有可读性
2 练习
1 设置变量bool_one的值为False or (not True) and True
2 设置变量bool_two的值为False and (not True) or True
3 设置变量bool_three的值为True and not (False or False)
4 设置变量bool_four的值为not (not True) or False and (not True)
5 设置变量bool_five的值为False or not (True and True)
[python]
bool_one = False or (not True) and True
bool_two = False and (not True) or True
bool_three = True and not (False or False)
bool_four = not (not True) or False and (not True)
bool_five = False or not (True and True)
第八节
1 练习：请至少使用and，or，not来完成以下的练习
[python]
# Use boolean expressions as appropriate on the lines below!
# Make me false!
bool_one = not ((1 and 2) or 3)
# Make me true!
bool_two = not (not((1 and 2) or 3))
# Make me false!
bool_three = not ((1 and 2) or 3)
# Make me true!
bool_four = not (not((1 and 2) or 3))
# Make me true!
bool_five = not (not((1 and 2) or 3)