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python-内置数据结构2

2016-12-11 19:39 369 查看
1、字符串--是不可变的
定义及初始化

In [577]: s = 'hello wolrd'

In [578]: s
Out[578]: 'hello wolrd'

In [579]: s = "hello python"

In [580]: s
Out[580]: 'hello python'

In [581]: s = '''hello'''

In [582]: s
Out[582]: 'hello'

In [583]: s = """hello"""

In [584]: s
Out[584]: 'hello'

In [585]:

In [585]: s = '''hello python
...: i like python'''

In [586]: s
Out[586]: 'hello python\ni like python'


转义
In [587]: s = 'i like \npython'

In [588]: s
Out[588]: 'i like \npython'

In [589]: print(s)
i like
python

In [590]: s = 'i\'m martin'

In [591]: s
Out[591]: "i'm martin"

In [592]: path = 'C:\\windows\nt\systemew'

In [593]: path
Out[593]: 'C:\\windows\nt\\systemew'

In [594]: print(path)
C:\windows
t\systemew

In [595]: path = 'C:\\windows\\nt\systemew'

In [596]: print(path)
C:\windows\nt\systemew

In [597]: path =r'C:\\windows\nt\systemew'  # 加r前缀代表此字符串是自然字符串, 不会转义

In [598]: print(path)
C:\\windows\nt\systemew


下标操作
In [599]: s
Out[599]: "i'm martin"

In [600]: s[3]
Out[600]: ' '

In [601]: s[0]
Out[601]: 'i'

In [602]: type(s[0])
Out[602]: str

In [603]:

In [603]: s = 'martin'

In [604]: for i in s:   #字符串是可迭代对象
...:     print(i)
...:
m
a
r
t
i
n

In [605]: list(s)
Out[605]: ['m', 'a', 'r', 't', 'i', 'n']


字符串的操作
In [607]: lst = ['i','am','martin']

In [608]: lst
Out[608]: ['i', 'am', 'martin']

In [609]: ' '.join(lst)
Out[609]: 'i am martin'

In [610]:

In [610]: s = 'i love python'

In [611]: s.split()
Out[611]: ['i', 'love', 'python']

In [612]: '      love python'.split()
Out[612]: ['love', 'python']

In [613]: '      love python'.split(' ')
Out[613]: ['', '', '', '', '', '', 'love', 'python']

In [614]: s.split(maxsplit=1)
Out[614]: ['i', 'love python']

In [615]: s = '''i am martin
...: i love python'''

In [616]: s.splitlines()
Out[616]: ['i am martin', 'i love python']

In [617]: 'i am martin'.partition(' ')
Out[617]: ('i', ' ', 'am martin')

In [618]: cfg = 'env = PATH=/usr/bin;$PATH'

In [619]: cfg.partition('=')
Out[619]: ('env ', '=', ' PATH=/usr/bin;$PATH')

In [620]: s = 'test'

In [621]: s.upper()
Out[621]: 'TEST'

In [622]: s.upper().lower()
Out[622]: 'test'

In [623]: s.title()
Out[623]: 'Test'

In [624]: s.center(30)
Out[624]: '             test             '
In [625]: s = 'hahahah   hehe'

In [626]: s.strip()
Out[626]: 'hahahah   hehe'
列表, 元组, 字符串, bytes, bytearray
都是顺序存储, 顺序访问的, 都是可迭代对象, 都可以通过索引访问
In [629]: list(enumerate([1,2,3]))
Out[629]: [(0, 1), (1, 2), (2, 3)]

In [630]: lst = list(range(10))

In [631]: lst
Out[631]: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

In [632]: lst[3]
Out[632]: 3

In [633]: lst[3:7]
Out[633]: [3, 4, 5, 6]

In [634]: lst[3:7:2]
Out[634]: [3, 5]

In [635]: lst[3:]
Out[635]: [3, 4, 5, 6, 7, 8, 9]

In [636]: lst[:7]
Out[636]: [0, 1, 2, 3, 4, 5, 6]

In [637]: lst[:]
Out[637]: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

In [638]: lst[8:5:-1]
Out[638]: [8, 7, 6]
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标签:  基础 Python