Python学习笔记 - ifelifelse-forin-while

if elif else

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

age = 20
if age >= 18:
	print('your age is', age)
	print('adult')

age = 3
if age >= 18:
	print('your age is', age)
	print('adult')
else: # 别忘了冒号
	print('your age is', age)
	print('teenager')

if age >= 18:
	print('adult')
elif age >= 6: # elif是else if的缩写
	print('teenager')
else:
	print('kid')

>>> birth = input('birth: ')
birth: 1992
>>> if birth < 2000:
...     print('00前')
... else:
...     print('00后')
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unorderable types: str() < int()
>>> s = input('birth')
birth 1992
>>> birth = int(s)
>>> if birth < 2000:
...     print('00前')
... else:
...     print('00后')
...
00前

height = 1.75
weight = 80.5
bmi = weight / (height * height)
if bmi <= 18.5:
	print('过轻')
elif bmi <= 25:
	print('正常')
elif bmi <= 28:
	print('过重')
elif bmi <= 32:
	print('肥胖')
else:
	print('严重肥胖')

for in

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

names = ['Michael', 'Bob', 'Tracy']
for name in names:
	print(name)
'''
Michael
Bob
Tracy
'''

sum = 0
for x in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]:
	sum = sum + x
print(sum)
'''
>>> list(range(5))
[0, 1, 2, 3, 4]
'''

sum = 0
for x in range(101):
	sum = sum + x
print(sum) # 5050

#计算100以内所有奇数之和
sum = 0
n = 99
while n > 0:
	sum = sum + n
	n = n - 2
print(sum) # 2500

#练习
L = ['Bart', 'Lisa', 'Adam']
for name in L:
	print('Hello,', name)
'''
Hello, Bart
Hello, Lisa
Hello, Adam
'''