数据类型方法
字符串是一个类,"hello world"是它的对象
常用方法:
- 移除空白
- 分割
- 长度
- 索引
- 切片
class str(basestring): def capitalize(self): """ 首字母变大写 """ (返回副本) def center(self, width, fillchar=None): """ 内容居中,width:总长度;fillchar:空白处填充内容,默认无 """ def count(self, sub, start=None, end=None): """ 子序列个数 """ def decode(self, encoding=None, errors=None): """ 解码 """ def encode(self, encoding=None, errors=None): """ 编码,针对unicode """ def endswith(self, suffix, start=None, end=None): """ 是否以 xxx 结束 """ def expandtabs(self, tabsize=None): """ 将tab转换成空格,默认一个tab转换成8个空格 """ (返回副本) def find(self, sub, start=None, end=None): """ 寻找子序列位置,如果没找到,返回 -1 """ def format(*args, **kwargs): # known special case of str.format """ 字符串格式化,动态参数,将函数式编程时细说 """ def index(self, sub, start=None, end=None): """ 子序列位置,如果没找到,报错 """ def isalnum(self): """ 是否是字母和数字 """ def isalpha(self): """ 是否是字母 """ def isdigit(self): """ 是否是数字 """ def islower(self): """ 是否小写 """ def isspace(self): def istitle(self): def isupper(self): def join(self, iterable): """ 连接 """ def ljust(self, width, fillchar=None): """ 内容左对齐,右侧填充 """ def lower(self): """ 变小写 """ (返回副本) def lstrip(self, chars=None): """ 移除左侧空白 """ (返回副本) def partition(self, sep): """ 分割,前,中,后三部分 """ def replace(self, old, new, count=None): """ 替换 """ (返回副本) def rfind(self, sub, start=None, end=None): def rindex(self, sub, start=None, end=None): def rjust(self, width, fillchar=None): def rpartition(self, sep): def rsplit(self, sep=None, maxsplit=None): def rstrip(self, chars=None): (返回副本) def split(self, sep=None, maxsplit=None): """ 分割, maxsplit最多分割几次 """ def splitlines(self, keepends=False): """ 根据换行分割 """ def startswith(self, prefix, start=None, end=None): """ 是否起始 """ def strip(self, chars=None): """ 移除两端空白 """ (返回副本) def swapcase(self): """ 大写变小写,小写变大写 """ def title(self): def translate(self, table, deletechars=None): """ 转换,需要先做一个对应表,最后一个表示删除字符集合 intab = "aeiou" outtab = "12345" trantab = maketrans(intab, outtab) str = "this is string example....wow!!!" print str.translate(trantab, 'xm') """ (返回副本) def upper(self): (返回副本) def zfill(self, width): """方法返回指定长度的字符串,原字符串右对齐,前面填充0。""" def _formatter_field_name_split(self, *args, **kwargs): # real signature unknown pass def _formatter_parser(self, *args, **kwargs): # real signature unknown pass def __add__(self, y): """ x.__add__(y) <==> x+y """ pass def __contains__(self, y): """ x.__contains__(y) <==> y in x """ pass def __eq__(self, y): """ x.__eq__(y) <==> x==y """ pass def __format__(self, format_spec): """ S.__format__(format_spec) -> string Return a formatted version of S as described by format_spec. """ return "" def __getattribute__(self, name): """ x.__getattribute__('name') <==> x.name """ pass def __getitem__(self, y): """ x.__getitem__(y) <==> x[y] """ pass def __getnewargs__(self, *args, **kwargs): # real signature unknown pass def __getslice__(self, i, j): """ x.__getslice__(i, j) <==> x[i:j] Use of negative indices is not supported. """ pass def __ge__(self, y): """ x.__ge__(y) <==> x>=y """ pass def __gt__(self, y): """ x.__gt__(y) <==> x>y """ pass def __hash__(self): """ x.__hash__() <==> hash(x) """ pass def __init__(self, string=''): # known special case of str.__init__ """ str(object='') -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. # (copied from class doc) """ pass def __len__(self): """ x.__len__() <==> len(x) """ pass def __le__(self, y): """ x.__le__(y) <==> x<=y """ pass def __lt__(self, y): """ x.__lt__(y) <==> x<y """ pass def __mod__(self, y): """ x.__mod__(y) <==> x%y """ pass def __mul__(self, n): """ x.__mul__(n) <==> x*n """ pass @staticmethod # known case of __new__ def __new__(S, *more): """ T.__new__(S, ...) -> a new object with type S, a subtype of T """ pass def __ne__(self, y): """ x.__ne__(y) <==> x!=y """ pass def __repr__(self): """ x.__repr__() <==> repr(x) """ pass def __rmod__(self, y): """ x.__rmod__(y) <==> y%x """ pass def __rmul__(self, n): """ x.__rmul__(n) <==> n*x """ pass def __sizeof__(self): """ S.__sizeof__() -> size of S in memory, in bytes """ pass def __str__(self): """ x.__str__() <==> str(x) """ pass str
list方法:
基本操作:
- 索引
- 切片
- 追加
- 删除
- 长度
- 切片
- 循环
- 包含
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
元组:带上枷锁的列表,方法同列表,但元组不可更改
如果想更新元组:temp=(1,2,3,4) temp=temp(:2)+('hello',)+temp(2:)
字典:{键:值,键:值。。。}
创建字典:
person = {"name": "mr.wu", 'age': 18} 或 person = dict({"name": "mr.wu", 'age': 18})
常用操作:
- 索引
- 新增
- 删除 del dict[key]
- 键、值、键值对
- 循环
- 长度
for i in 字典: print(i) #默认输出key for k,v in 字典: print(k) print(v)
set:set集合,是一个无序且不重复的元素集合
创建:a={'a','b',c'}或a=set()或a=set(['x','y','z'])
class set(object): """ set() -> new empty set object set(iterable) -> new set object Build an unordered collection of unique elements. """ def add(self, *args, **kwargs): # real signature unknown """ Add an element to a set,添加一个元素 This has no effect if the element is already present. """ pass def clear(self, *args, **kwargs): # real signature unknown """ Remove all elements from this set. 清除内容""" pass def copy(self, *args, **kwargs): # real signature unknown """ Return a shallow copy of a set. 浅拷贝 """ pass def difference(self, *args, **kwargs): # real signature unknown """ Return the difference of two or more sets as a new set.c=a.diffrence(b):找A中存在,B中不存在,并创建个副本给一个新的变量 (i.e. all elements that are in this set but not the others.) """ pass def difference_update(self, *args, **kwargs): # real signature unknown """ Remove all elements of another set from this set. 从当前集合中删除和B中相同的元素""",更新自身 pass def discard(self, *args, **kwargs): # real signature unknown """ Remove an element from a set if it is a member. If the element is not a member, do nothing. 移除指定元素,不存在的话也不报错 """ pass def intersection(self, *args, **kwargs): # real signature unknown """ Return the intersection of two sets as a new set. 交集,生成副本赋值给新变量 (i.e. all elements that are in both sets.) """ pass def intersection_update(self, *args, **kwargs): # real signature unknown """ Update a set with the intersection of itself and another. 取交集并更更新到A中 """ pass def isdisjoint(self, *args, **kwargs): # real signature unknown """ Return True if two sets have a null intersection. 如果没有交集,返回True,有交集返回False""" pass def issubset(self, *args, **kwargs): # real signature unknown """ Report whether another set contains this set. 是否是子序列""" a.issubset(b) a是否是b的子序列 pass def issuperset(self, *args, **kwargs): # real signature unknown """ Report whether this set contains another set. 是否是父序列""" pass //a.issuperset(b) a是否是b的父序列 def pop(self, *args, **kwargs): # real signature unknown """ Remove and return an arbitrary set element. Raises KeyError if the set is empty. 移除元素 """集合无序,理解为随机移除元素 pass def remove(self, *args, **kwargs): # real signature unknown """ Remove an element from a set; it must be a member. If the element is not a member, raise a KeyError. 移除指定元素,不存在保错 """ pass def symmetric_difference(self, *args, **kwargs): # real signature unknown """ Return the symmetric difference of two sets as a new set. 对称差集 a有b没有 或者 b有a没有的放到一起 (i.e. all elements that are in exactly one of the sets.) """ pass def symmetric_difference_update(self, *args, **kwargs): # real signature unknown """ Update a set with the symmetric difference of itself and another. 对称差集,并更新到a中 """ pass def union(self, *args, **kwargs): # real signature unknown """ Return the union of sets as a new set. 并集 创建副本 (i.e. all elements that are in either set.) """ pass def update(self, *args, **kwargs): # real signature unknown """ Update a set with the union of itself and others. 更新 """ pass
其他:
enumrate为可迭代的对象添加序号
li = [11,22,33] for k,v in enumerate(li, 1): #默认从0开始自增,这里是从1开始自增 print(k,v) #打印 1,11 2,22 3,33
range和xrange
指定范围,生成指定的数字
2.7中range(1,10),直接就创建1-9,xrange(1,10),只有在迭代的时候才创建1-9,提高效率
print range(1, 10) # 结果:[1, 2, 3, 4, 5, 6, 7, 8, 9] print range(1, 10, 2) # 结果:[1, 3, 5, 7, 9] print range(30, 0, -2) # 结果:[30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2]
3.5中的range就相当于2.7中的xrange