python基本数据类型——list

一、创建列表:

li = []
li = list()
name_list = ['alex', 'seven', 'eric'] name_list = list(['alex', 'seven', 'eric'])

二、基本操作:

#append追加
name_list = ["zhangyanlin","suoning","nick"]
name_list.append('zhang')
print(name_list) #count制定字符出现几次
name_list = ["zhangyanlin","suoning","nick"]
name_list.append('zhang')
name_list.append('zhang')
name_list.append('zhang')
print(name_list.count('zhang')) #extend可扩展,批量往里加数据
name_list = ["zhangyanlin","suoning","nick"]
name = ["aylin","zhang","yan","lin"]
name_list.extend(name)
print(name_list) #index找到字符所在的位置
name_list = ["zhangyanlin","suoning","nick"]
print(name_list.index('nick')) #insert插入,往索引里面插入值
name_list = ["zhangyanlin","suoning","nick"]
name_list.insert(1,"zhang")
print(name_list) #pop在原列表中移除掉最后一个元素,并赋值给另一个变量
name_list = ["zhangyanlin","suoning","nick"]
name = name_list.pop()
print(name) #remove移除,只移除从左边找到的第一个
name_list = ["zhangyanlin","suoning","nick"]
name_list.remove('nick')
print(name_list) #reverse反转
name_list = ["zhangyanlin","suoning","nick"]
name_list.reverse()
print(name_list) #del删除其中元素,删除1到3之间的
name_list = ["zhangyanlin","suoning","nick"]
del name_list[1:3]
print(name_list)
#join将列表元素用指定字符串连接
name_list = ["you","are","good"]
s = " ".join(name_list)
print(name_list)
# you are good
class list(object):
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
"""
def append(self, p_object): # real signature unknown; restored from __doc__
""" L.append(object) -- append object to end """
pass def count(self, value): # real signature unknown; restored from __doc__
""" L.count(value) -> integer -- return number of occurrences of value """
return 0 def extend(self, iterable): # real signature unknown; restored from __doc__
""" L.extend(iterable) -- extend list by appending elements from the iterable """
pass def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
"""
L.index(value, [start, [stop]]) -> integer -- return first index of value.
Raises ValueError if the value is not present.
"""
return 0 def insert(self, index, p_object): # real signature unknown; restored from __doc__
""" L.insert(index, object) -- insert object before index """
pass def pop(self, index=None): # real signature unknown; restored from __doc__
"""
L.pop([index]) -> item -- remove and return item at index (default last).
Raises IndexError if list is empty or index is out of range.
"""
pass def remove(self, value): # real signature unknown; restored from __doc__
"""
L.remove(value) -- remove first occurrence of value.
Raises ValueError if the value is not present.
"""
pass def reverse(self): # real signature unknown; restored from __doc__
""" L.reverse() -- reverse *IN PLACE* """
pass def sort(self, cmp=None, key=None, reverse=False): # real signature unknown; restored from __doc__
"""
L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*;
cmp(x, y) -> -1, 0, 1
"""
pass def __add__(self, y): # real signature unknown; restored from __doc__
""" x.__add__(y) <==> x+y """
pass def __contains__(self, y): # real signature unknown; restored from __doc__
""" x.__contains__(y) <==> y in x """
pass def __delitem__(self, y): # real signature unknown; restored from __doc__
""" x.__delitem__(y) <==> del x[y] """
pass def __delslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__delslice__(i, j) <==> del x[i:j] Use of negative indices is not supported.
"""
pass def __eq__(self, y): # real signature unknown; restored from __doc__
""" x.__eq__(y) <==> x==y """
pass def __getattribute__(self, name): # real signature unknown; restored from __doc__
""" x.__getattribute__('name') <==> x.name """
pass def __getitem__(self, y): # real signature unknown; restored from __doc__
""" x.__getitem__(y) <==> x[y] """
pass def __getslice__(self, i, j): # real signature unknown; restored from __doc__
"""
x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported.
"""
pass def __ge__(self, y): # real signature unknown; restored from __doc__
""" x.__ge__(y) <==> x>=y """
pass def __gt__(self, y): # real signature unknown; restored from __doc__
""" x.__gt__(y) <==> x>y """
pass def __iadd__(self, y): # real signature unknown; restored from __doc__
""" x.__iadd__(y) <==> x+=y """
pass def __imul__(self, y): # real signature unknown; restored from __doc__
""" x.__imul__(y) <==> x*=y """
pass def __init__(self, seq=()): # known special case of list.__init__
"""
list() -> new empty list
list(iterable) -> new list initialized from iterable's items
# (copied from class doc)
"""
pass def __iter__(self): # real signature unknown; restored from __doc__
""" x.__iter__() <==> iter(x) """
pass def __len__(self): # real signature unknown; restored from __doc__
""" x.__len__() <==> len(x) """
pass def __le__(self, y): # real signature unknown; restored from __doc__
""" x.__le__(y) <==> x<=y """
pass def __lt__(self, y): # real signature unknown; restored from __doc__
""" x.__lt__(y) <==> x<y """
pass def __mul__(self, n): # real signature unknown; restored from __doc__
""" x.__mul__(n) <==> x*n """
pass @staticmethod # known case of __new__
def __new__(S, *more): # real signature unknown; restored from __doc__
""" T.__new__(S, ...) -> a new object with type S, a subtype of T """
pass def __ne__(self, y): # real signature unknown; restored from __doc__
""" x.__ne__(y) <==> x!=y """
pass def __repr__(self): # real signature unknown; restored from __doc__
""" x.__repr__() <==> repr(x) """
pass def __reversed__(self): # real signature unknown; restored from __doc__
""" L.__reversed__() -- return a reverse iterator over the list """
pass def __rmul__(self, n): # real signature unknown; restored from __doc__
""" x.__rmul__(n) <==> n*x """
pass def __setitem__(self, i, y): # real signature unknown; restored from __doc__
""" x.__setitem__(i, y) <==> x[i]=y """
pass def __setslice__(self, i, j, y): # real signature unknown; restored from __doc__
"""
x.__setslice__(i, j, y) <==> x[i:j]=y Use of negative indices is not supported.
"""
pass def __sizeof__(self): # real signature unknown; restored from __doc__
""" L.__sizeof__() -- size of L in memory, in bytes """
pass __hash__ = None list

list源码

三、数据类型转换

字符串转列表

s = "你好morra"
li = list(s)
print(li) OUTPUT:
['你', '好', 'm', 'o', 'r', 'r', 'a']

元组转列表

tu = ("你好","alex")
li = list(tu)
print(li) OUTPUT:
['你好', 'alex']

字典转列表

dic = {'k1':'hello','k2':'morra'}
l3 = list(dic) #字典在循环的时候默认只循环key
print(l3) l4 = list(dic.values())
print(l4) l5 = list(dic.items())
print(l5) OUTPUT:
['k2', 'k1']
['morra', 'hello']
[('k2', 'morra'), ('k1', 'hello')]

四、可迭代性

l = ['i', 'am', 'spark']
# 可以被for循环所迭代
for i in l:
print (i)
# i am spark

五、可嵌套性

li = ['字符串',('tuple','hh'),{"key1":"value1","key2":"value2"}]
print(li[2]["key1"])
#输出 value1
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