for 和 while 循环

Python 金融进阶

Kennedy Behrman

Data Engineer, Author, Founder

重复执行代码块

CUSIP

037833100

17275R102

68389X105

股票代码

AAPL

CSCO

ORCL

循环。

for 循环

while 循环

语句组成部分

<控制语句>
    <代码块>

执行 1

执行 2

执行 3

for 循环

for <variable> in <sequence>:

for x in [0, 1, 2]:

d = {'key': 'value1'}
for x in d:

for x in "ORACLE":

列表示例

for x in [0, 1, 2]:
    print(x)

0
1
2

字典示例

symbols = {'037833100': 'AAPL',
           '17275R102': 'CSCO'
           '68389X105': 'ORCL'}
for k in symbols:
    print(symbols[k])

AAPL
CSCO
ORCL

字符串示例

for x in "ORACLE":
    print(x)

O
R
A
C
L
E

while 控制语句

while <expression>:

while 示例

x = 0

while x < 5:
    print(x)
    x = (x + 1)

无限循环

x = 0

while x <= 5:
     print(x)

用 continue 跳过

for x in [0, 1, 2, 3]:
   if x == 2:
       continue
   print(x)

0
1
3

用 break 停止。

while True:
    transaction = get_transaction()
    if transaction['symbol'] == 'ORCL':
        print('The current symbol is ORCL, break now')
        break
    print('Not ORCL')

Not ORCL
Not ORCL
Not ORCL
The current symbol is ORCL, break now

练习 for 和 while 循环！

Python 金融进阶