浅谈python中数据解析

import os; — python自带
print(os.getcwd()) — 获得当前工作目录
os.chdir(‘/users/longlong/documents’) — 转换到/users/longlong/documents目录
os.path.join(parm1, parm2,…) — 从一个或多个路径片段中构造一个路径名。
os.path.expanduser() — 用来将包含～符号的路径扩展为完整的路径

代码如下:

>>> pathname = ‘/users/pilgrim/peintopython3/examples/humansize.py’
>>> os.path.split(pathname) –(‘/users/pilgrim/peintopython3/examples’, ‘humansize.py’）罗列目录内容构造绝对路径

代码如下:

>>> import os
>>> print(os.getcwd())
/users/longlong/documents
>>> os.chdir(“./python/”)
>>> os.getcwd()
‘/users/longlong/documents/python’
>>> print(os.path.realpath(‘whileloop.py’)
)
/users/longlong/documents/python/whileloop.py
>>> print(os.path.realpath(“whileloop.py”))
/users/longlong/documents/python/whileloop.py
>>>

列表解析

代码如下:

>>> [os.path.realpath(f) for f in glob.glob(“*.py”)]
[‘/users/longlong/documents/python/indices_over_two_objects.py’, ‘/users/longlong/documents/python/loops_over_indices.py’, ‘/users/longlong/documents/python/while_loops.py’]
>>> [f for f in glob.glob(“*.py”) if os.stat(f).st_size > 700]
[‘indices_over_two_objects.py’, ‘while_loops.py’]
1

字典解析

>>> metadat_dict = { f:os.stat(f) for f in glob.glob(‘*.py’)}
>>> type(metadat_dict)

>>> list(metadat_dict.keys())
[‘indices_over_two_objects.py’, ‘while_loops.py’, ‘loops_over_indices.py’]
>>> metadat_dict[‘indices_over_two_objects.py’].st_size
871

>>> list(metadat_dict.keys())
[‘indices_over_two_objects.py’, ‘while_loops.py’, ‘loops_over_indices.py’]
>>> a_dict = {‘a’:1, ‘b’:2,’c’:3}
>>> {value:key for key,value in a_dict.items()}
{1: ‘a’, 2: ‘b’, 3: ‘c’}

集合解析

>>> a_set = set(range(10))
>>> a_set
{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
>>> {x**2 for x in a_set}
{0, 1, 64, 4, 36, 9, 16, 49, 81, 25}
>>> {x for x in a_set if x%2 == 0 }
{0, 8, 2, 4, 6}
>>> {2**x for x in range(10)}
{32, 1, 2, 64, 4, 128, 256, 512, 8, 16}

以上所述就是本文的全部内容了，希望大家能够喜欢。