python基本数据类型
基本数据类型
数字
int（整型）
在32位机器上，整数的位数为32位，取值范围为-2**31～2**31-1，即-2147483648～2147483647
在64位系统上，整数的位数为64位，取值范围为-2**63～2**63-1，即-9223372036854775808～9223372036854775807
字符串
字符串常用功能：
格式化输出：字符串占位符 %s
%s 字符串
%d 数字
%f 浮点数
%r 原生字符，非转义
>>> msg="my name is %s,age is %d" %("tom",23) >>> print(msg) my name is tom,age is 23 >>> >>> msg="my name is %s,age is %f" %("tom",23) >>> print(msg) my name is tom,age is 23.000000 >>> >>> msg="my name is %s,age is %s" %("tom",23) >>> print(msg) my name is tom,age is 23 >>> >>> >>> msg="my name is %s,age is %d" %("tom","23") Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: %d format: a number is required, not str >>> >>> msg="my name is %s,age is %s" %("tom","23\n\tsdf") >>> print(msg) my name is tom,age is 23 sdf >>> >>> msg="my name is %s,age is %r" %("tom","23\n\tsdf") >>> print(msg) my name is tom,age is '23\n\tsdf'
"hello world"
- 移除空白
- 分割
- 长度
- 索引
- 切片
class str(basestring): """ str(object='') -> string Return a nice string representation of the object. If the argument is a string, the return value is the same object. """ def capitalize(self): """ 首字母变大写 """ """ S.capitalize() -> string Return a copy of the string S with only its first character capitalized. """ return "" 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 """ """ S.center(width[, fillchar]) -> string Return S centered in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def count(self, sub, start=None, end=None): """ 子序列个数 """ """ S.count(sub[, start[, end]]) -> int Return the number of non-overlapping occurrences of substring sub in string S[start:end]. Optional arguments start and end are interpreted as in slice notation. """ return 0 def decode(self, encoding=None, errors=None): """ 解码 """ """ S.decode([encoding[,errors]]) -> object Decodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is 'strict' meaning that encoding errors raise a UnicodeDecodeError. Other possible values are 'ignore' and 'replace' as well as any other name registered with codecs.register_error that is able to handle UnicodeDecodeErrors. """ return object() def encode(self, encoding=None, errors=None): """ 编码，针对unicode """ """ S.encode([encoding[,errors]]) -> object Encodes S using the codec registered for encoding. encoding defaults to the default encoding. errors may be given to set a different error handling scheme. Default is 'strict' meaning that encoding errors raise a UnicodeEncodeError. Other possible values are 'ignore', 'replace' and 'xmlcharrefreplace' as well as any other name registered with codecs.register_error that is able to handle UnicodeEncodeErrors. """ return object() def endswith(self, suffix, start=None, end=None): """ 是否以 xxx 结束 """ """ S.endswith(suffix[, start[, end]]) -> bool Return True if S ends with the specified suffix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. suffix can also be a tuple of strings to try. """ return False def expandtabs(self, tabsize=None): """ 将tab转换成空格，默认一个tab转换成8个空格 """ """ S.expandtabs([tabsize]) -> string Return a copy of S where all tab characters are expanded using spaces. If tabsize is not given, a tab size of 8 characters is assumed. """ return "" def find(self, sub, start=None, end=None): """ 寻找子序列位置，如果没找到，返回 -1 """ """ S.find(sub [,start [,end]]) -> int Return the lowest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 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 """ """ S.format(*args, **kwargs) -> string Return a formatted version of S, using substitutions from args and kwargs. The substitutions are identified by braces ('{' and '}'). """ pass def index(self, sub, start=None, end=None): """ 子序列位置，如果没找到，报错 """ S.index(sub [,start [,end]]) -> int Like S.find() but raise ValueError when the substring is not found. """ return 0 def isalnum(self): """ 是否是字母和数字 """ """ S.isalnum() -> bool Return True if all characters in S are alphanumeric and there is at least one character in S, False otherwise. """ return False def isalpha(self): """ 是否是字母 """ """ S.isalpha() -> bool Return True if all characters in S are alphabetic and there is at least one character in S, False otherwise. """ return False def isdigit(self): """ 是否是数字 """ """ S.isdigit() -> bool Return True if all characters in S are digits and there is at least one character in S, False otherwise. """ return False def islower(self): """ 是否小写 """ """ S.islower() -> bool Return True if all cased characters in S are lowercase and there is at least one cased character in S, False otherwise. """ return False def isspace(self): """ S.isspace() -> bool Return True if all characters in S are whitespace and there is at least one character in S, False otherwise. """ return False def istitle(self): """ S.istitle() -> bool Return True if S is a titlecased string and there is at least one character in S, i.e. uppercase characters may only follow uncased characters and lowercase characters only cased ones. Return False otherwise. """ return False def isupper(self): """ S.isupper() -> bool Return True if all cased characters in S are uppercase and there is at least one cased character in S, False otherwise. """ return False def join(self, iterable): """ 连接 """ """ S.join(iterable) -> string Return a string which is the concatenation of the strings in the iterable. The separator between elements is S. """ return "" def ljust(self, width, fillchar=None): """ 内容左对齐，右侧填充 """ """ S.ljust(width[, fillchar]) -> string Return S left-justified in a string of length width. Padding is done using the specified fill character (default is a space). """ return "" def lower(self): """ 变小写 """ """ S.lower() -> string Return a copy of the string S converted to lowercase. """ return "" def lstrip(self, chars=None): """ 移除左侧空白 """ """ S.lstrip([chars]) -> string or unicode Return a copy of the string S with leading whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def partition(self, sep): """ 分割，前，中，后三部分 """ """ S.partition(sep) -> (head, sep, tail) Search for the separator sep in S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return S and two empty strings. """ pass def replace(self, old, new, count=None): """ 替换 """ """ S.replace(old, new[, count]) -> string Return a copy of string S with all occurrences of substring old replaced by new. If the optional argument count is given, only the first count occurrences are replaced. """ return "" def rfind(self, sub, start=None, end=None): """ S.rfind(sub [,start [,end]]) -> int Return the highest index in S where substring sub is found, such that sub is contained within S[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 on failure. """ return 0 def rindex(self, sub, start=None, end=None): """ S.rindex(sub [,start [,end]]) -> int Like S.rfind() but raise ValueError when the substring is not found. """ return 0 def rjust(self, width, fillchar=None): """ S.rjust(width[, fillchar]) -> string Return S right-justified in a string of length width. Padding is done using the specified fill character (default is a space) """ return "" def rpartition(self, sep): """ S.rpartition(sep) -> (head, sep, tail) Search for the separator sep in S, starting at the end of S, and return the part before it, the separator itself, and the part after it. If the separator is not found, return two empty strings and S. """ pass def rsplit(self, sep=None, maxsplit=None): """ S.rsplit([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string, starting at the end of the string and working to the front. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator. """ return [] def rstrip(self, chars=None): """ S.rstrip([chars]) -> string or unicode Return a copy of the string S with trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def split(self, sep=None, maxsplit=None): """ 分割， maxsplit最多分割几次 """ """ S.split([sep [,maxsplit]]) -> list of strings Return a list of the words in the string S, using sep as the delimiter string. If maxsplit is given, at most maxsplit splits are done. If sep is not specified or is None, any whitespace string is a separator and empty strings are removed from the result. """ return [] def splitlines(self, keepends=False): """ 根据换行分割 """ """ S.splitlines(keepends=False) -> list of strings Return a list of the lines in S, breaking at line boundaries. Line breaks are not included in the resulting list unless keepends is given and true. """ return [] def startswith(self, prefix, start=None, end=None): """ 是否起始 """ """ S.startswith(prefix[, start[, end]]) -> bool Return True if S starts with the specified prefix, False otherwise. With optional start, test S beginning at that position. With optional end, stop comparing S at that position. prefix can also be a tuple of strings to try. """ return False def strip(self, chars=None): """ 移除两段空白 """ """ S.strip([chars]) -> string or unicode Return a copy of the string S with leading and trailing whitespace removed. If chars is given and not None, remove characters in chars instead. If chars is unicode, S will be converted to unicode before stripping """ return "" def swapcase(self): """ 大写变小写，小写变大写 """ """ S.swapcase() -> string Return a copy of the string S with uppercase characters converted to lowercase and vice versa. """ return "" def title(self): """ S.title() -> string Return a titlecased version of S, i.e. words start with uppercase characters, all remaining cased characters have lowercase. """ return "" 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') """ """ S.translate(table [,deletechars]) -> string Return a copy of the string S, where all characters occurring in the optional argument deletechars are removed, and the remaining characters have been mapped through the given translation table, which must be a string of length 256 or None. If the table argument is None, no translation is applied and the operation simply removes the characters in deletechars. """ return "" def upper(self): """ S.upper() -> string Return a copy of the string S converted to uppercase. """ return "" 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。""" """ S.zfill(width) -> string Pad a numeric string S with zeros on the left, to fill a field of the specified width. The string S is never truncated. """ return "" 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 复制代码
names = "tom Li english ie" #首字母大写 print(names.capitalize()) #大写变小写 print(names.casefold()) #字符串总长度为10，不够用#代替 print(names.center(11,'#')) #统计个数 print(names.count("i")) print(names.count("i",0,10)) #以什么结束打印真和假 print(names.endswith("ie")) #查找，找到反应位置 print(names.find('L')) #格式化 msg = "my name is {0} , and age is {1} years old" msg2 = "my name is {name} , and age is {age} years old" print(msg.format('tom',25)) print(msg2.format(age=25,name='tom')) ##是否只包含字母， print("af".isalpha()) #是否只包含字母和数字 print("af123".isalnum()) #是否正整数 print("2".isdigit()) #是不是一个合法的变量名 print('t_time'.isidentifier()) #是否小写 print("tom".islower()) #是否大写 print("tom".isupper()) #是否数字 print(("tom".isnumeric())) #join链接 print(','.join("english")) print(','.join(["tom",'lily','lucy'])) #添加，不够 print("tom".ljust(20,'-')) print("tom".rjust(20,'-')) #大写变小写 print("TOM".lower()) #去掉左右空格 print(" tom is english ".strip()) #去掉左空格 print(" tom is english ".lstrip()) #去掉右空格 print(" tom is english ".rstrip()) #按某个字母分割 print("tom is good".partition("s")) #替换 print("tom is good".replace("is","IS")) #分割 \n print("tom \n is \ngood".split())
布尔值
真或假 True False
1 或 0
列表
创建列表：
name_list=['tom','lily','jack']
或
name_list = list(['tom','lily','jack'])
列表功能：
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
申明： >>> names = ["alex","jack","tom"] 取值： >>> names[0] 'alex' >>> names[-2] 'jack' 更改值： >>> names[0] = "wuwi" >>> names ['wuwi', 'jack', 'tom'] 增加： >>> names.append("sunli") >>> names ['wuwi', 'jack', 'tom', 'sunli'] 在某个位置插入值： >>> names.insert(2,"yanli"); >>> names ['wuwi', 'jack', 'yanli', 'tom', 'sunli'] 删除值： >>> del names[2] >>> names ['wuwi', 'jack', 'tom', 'sunli'] 删除值： >>> names.remove("tom"); >>> names ['wuwi', 'jack', 'sunli'] 索引： >>> names.index("jack") 1 >>> names[1] = "JACK" >>> names ['wuwi', 'JACK', 'sunli'] >>> names[names.index("sunli")] = "zhangsan" >>> names ['wuwi', 'JACK', 'zhangsan'] >>> names.append("JACK"); >>> names ['wuwi', 'JACK', 'zhangsan', 'JACK'] >>> 统计个数： >>> names.count("JACK"); 2 >>> names.index("JACK") 1 >>> names ['wuwi', 'JACK', 'zhangsan', 'JACK'] 排序： >>> names.sort() >>> names ['JACK', 'JACK', 'wuwi', 'zhangsan'] 反排序： >>> names.reverse() >>> names ['zhangsan', 'wuwi', 'JACK', 'JACK'] >>> 取几个值： >>> names[2:4] ['JACK', 'JACK'] >>> names[-3] 'wuwi' >>> names[-1:-3] [] >>> names[-3:-1] ['wuwi', 'JACK'] 按步长取值 >>> names ['zhangsan', 'wuwi', 'JACK', 'liwu', 'JACK', 'tom'] >>> names[0:-1:2] ['zhangsan', 'JACK', 'JACK']
元祖
元组其实跟列表差不多，也是存一组数，只不是它一旦创建，便不能再修改，所以又叫只读列表
语法
names = ("tom","jack","eric")
它只有2个方法，一个是count,一个是index，完毕。
字典
字典特点： 无序，key天生去重，查询效率高
names = { "st1":{"name":"alex","age":22,"hobbie":"girl"}, "st2":"tom", "st3":"lily", } print(names) print(names["st1"]["age"]) #判断key值是否存在 print("st2" in names) #没有返回 none,有就取出值 print(names.get("st5")) #add 增加 names["st4"] = ["kai",23,"boy"] print(names) #修改 names["st4"][0] = ["KAI"] print(names) #删除，有值，会返回删除值，无值可以指定返回值 print(names) print(names.pop("st2")) print(names) print(names.pop("st2","ok")) ##del删除 del names["st3"] print(names) #fromkeys能是列表变成key值 names=["tom","jack","lily"] print(dict.fromkeys(names,0)) #################### names = { "st1":{"name":"alex","age":22,"hobbie":"girl"}, "st2":"tom", "st3":"lily", } #items,做字典循环 for key in names: ##尽量用这种效率高 print(key,names[key]) ##效率低 for k,v in names.items(): print(k,v) ##取所有key值，value值 print(names.keys()) print('-------------') print(names.values()) ###随机删除一个 # print(names.popitem()) ###有取出，并返回，没有创建默认设置，都有返回值 print(names) print(names.setdefault("st3")) print(names.setdefault("st6","tttt")) print(names) ###合并两个字典，字典无序 d1 = {"kk":1,"bb":2,"cc":3} d2 = {"kk":7,"rr":8} d1.update(d2) print(d1)
深浅copy
#深浅拷贝，应用于银行账户，值会发生变化 # names = { # "st1":{"name":"alex","age":22}, # "st2":"tom", # "st3":"lily", # } # # n2 =names.copy() # # names["st2"]="RAIN" # names["st1"]["age"]=56 # print(names) # print(n2) {'st1': {'name': 'alex', 'age': 56}, 'st2': 'RAIN', 'st3': 'lily'} {'st1': {'name': 'alex', 'age': 56}, 'st2': 'tom', 'st3': 'lily'} #######################银行共享账户，tom ，liliy场景 import copy cr_card1={"name":"tom","acc":{"id":23333,"balance":1000}} cr_card2=cr_card1.copy() ##浅copy cr_card2["name"]="lily" #################深拷贝，要 import copy cr_card3=copy.deepcopy(cr_card1) ##深copy，完全copy print(cr_card1) print(cr_card2) print(cr_card3) cr_card1["acc"]["balance"] -=300 cr_card2["acc"]["balance"] -=500 print(cr_card1) print(cr_card2) print(cr_card1) print(cr_card2) print(cr_card3) {'name': 'tom', 'acc': {'id': 23333, 'balance': 1000}} {'name': 'lily', 'acc': {'id': 23333, 'balance': 1000}} {'name': 'tom', 'acc': {'id': 23333, 'balance': 1000}} {'name': 'tom', 'acc': {'id': 23333, 'balance': 200}} {'name': 'lily', 'acc': {'id': 23333, 'balance': 200}} {'name': 'tom', 'acc': {'id': 23333, 'balance': 200}} {'name': 'lily', 'acc': {'id': 23333, 'balance': 200}} {'name': 'tom', 'acc': {'id': 23333, 'balance': 1000}}
运算符
1、算数运算：
2、比较运算：
3、赋值运算：
4、逻辑运算：
5、成员运算：
