Python高階特性

2021-07-13 12:38:32 字數 2573 閱讀 7799

l = ['csx', 'sarah', 'tracy', 'bob', 'jack']

print [l[0], l[1], l[2]]

# 輸出:['csx', 'sarah', 'tracy']

l[0:3]

# 輸出:['csx', 'sarah', 'tracy']

如果第乙個索引是0,還可以省略:

print l[-2:]

# 輸出:['bob', 'jack']

print l[-2:-1]

# 輸出:['bob']

d = 

for key in d:

print key

# 輸出:

# a

# c

# b

for ch in 'abc':

print ch

# 輸出:

# a

# b

# c

for i, value

in enumerate(['a', 'b', 'c']):

print i, value

# 輸出:

0 a1 b

2 c

range

(1, 11)

[x*x for x in

range

(1, 11)

]

[x * x for x in

range(1, 11

) if x % 2 == 0]

[m + n for m in

'abc'

for n in

'xyz']

# 輸出:['ax', 'ay', 'az', 'bx', 'by', 'bz', 'cx', 'cy', 'cz']

import os # 匯入os模組,模組的概念後面講到

[d for d in os.listdir('.')] # os.listdir可以列出檔案和目錄

d = 

for k, v in d.iteritems():

print k, '=', v

"""輸出:

y = b

x = a

z = c

"""

d = 

[k + '=' + v for k, v in d.iteritems()]

# 輸出:['y=b', 'x=a', 'z=c']

l = [x * x for x in

range(10)]

print

l# 輸出:[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

g = (x * x for x in

range(10))

print

g# 輸出:at 0x104feab40>

print g.next()

# 輸出:0

.....

g = (x * x for x in range(10))

for n in g:

print n

"""輸出:01

491625

3649

6481

"""

def fib

(max)

: n, a, b = 0, 0, 1

while n < max:

print b

a, b = b, a + b

n = n + 1

def fib

(max)

: n, a, b = 0, 0, 1

while n < max:

yield b

a, b = b, a + b

n = n + 1

def

ood():

print

"step1"

yield

1print

"step2"

yield

2print

"step3"

yield

5o = ood()

print o.next()

print o.next()

print o.next()

"""step1

1step2

2step3

5"""

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