Python 基础第三天（set、collections、有序字典、队列、深浅拷贝、函数、lambda表达式、文件操作）
Set集合#是一个无序且不重复的元素集合，只需关注value
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 #添加一个元素，如果添加set里面有的元素将会过滤掉 s1 = set() s1.add(123) s1.add(123) print(s1) {123} """ Add an element to a set. This has no effect if the element is already present. """ pass def clear(self, *args, **kwargs): # real signature unknown #清空 """ Remove all elements from this set. """ pass def copy(self, *args, **kwargs): # real signature unknown #浅拷贝 """ Return a shallow copy of a set. """ pass def difference(self, *args, **kwargs): # real signature unknown #差集，两个集合中不相同的值生成新集合 s = set((1,2,3,4)) t = set((1,2,3,4,5)) b = t.difference(s)#返回一个新的set包含t中有但是s中没有的元素 print(b) {5} b = s.difference(t)#返回一个新的set包含s中有但是t中没有的元素 print(b) set() """ Return the difference of two or more sets as a new set. (i.e. all elements that are in this set but not the others.) """ pass def difference_update(self, *args, **kwargs): # real signature unknown #删除当前set中的所包含在参数集合中的元素 s = set((1,2,3)) t = set((1,2,3,4,5)) t.difference_update(s)#返回删除set “s”中的元素的set “t” print(t) {4, 5} """ Remove all elements of another set from this set. """ pass def discard(self, *args, **kwargs): # real signature unknown #移除 t = set((1,2,3,4,5)) t.discard(5)#如果在set “t”中存在元素5，则删除 print(t) {1, 2, 3, 4} """ Remove an element from a set if it is a member. If the element is not a member, do nothing. """ pass def intersection(self, *args, **kwargs): # real signature unknown #取交集，生成新的集合 s = set((1,2,3)) t = set((1,2,3,4,5)) a = s.intersection(t) b = t.intersection(s)#返回set "s"和 set “t”中共有元素 print(a,b) {1, 2, 3} {1, 2, 3} """ Return the intersection of two sets as a new set. (i.e. all elements that are in both sets.) """ pass def intersection_update(self, *args, **kwargs): # real signature unknown #取交集，修改原集合 s = set((1,2,3)) t = set((1,2,3,4,5)) s.intersection_update(t)#返回只保留含有set “t”中元素的set “s” print(t) {1, 2, 3, 4, 5} """ Update a set with the intersection of itself and another. """ pass def isdisjoint(self, *args, **kwargs): # real signature unknown #如果没有交集，返回True s1 = set(["alex","eric","tony","fdsf"]) s2 = set(["hjk","fds","alex","tony"]) a = s1.isdisjoint(s2) print(a) False """ Return True if two sets have a null intersection. """ pass def issubset(self, *args, **kwargs): # real signature unknown #是否是子集 s = set((1,2,3,4)) t = set((1,2,3,4,5)) a = s.issubset(t)#测试是否s中的每一个元素都在t中 print(a) True """ Report whether another set contains this set. """ pass def issuperset(self, *args, **kwargs): # real signature unknown #是否是父集 s = set((1,2,3,4)) t = set((1,2,3,4,5)) a = s.issuperset(t)#测试是否t中的每一个元素都在s中 print(a) False """ Report whether this set contains another set. """ pass def pop(self, *args, **kwargs): # real signature unknown #删除任意一个，有返回值 s1 = set(["alex","eric","tony","fdsf"]) s2 = set(["hjk","fds","alex","tony"]) a = s2.pop()#随机删除一个值，并将删除的值返回 print(a) print(s1,s2) alex {'tony', 'eric', 'fdsf', 'alex'} {'tony', 'fds', 'hjk'} """ Remove and return an arbitrary set element. Raises KeyError if the set is empty. """ pass def remove(self, *args, **kwargs): # real signature unknown #删除指定元素，无返回值 s2 = set(["hjk","fds","alex","tony"]) a = s2.remove("hjk")#从set “s2”中删除指定元素，无返回值；如果不存在则引发keyerror print(a) print(s1,s2) None {'tony', 'fds', 'alex'} """ Remove an element from a set; it must be a member. If the element is not a member, raise a KeyError. """ pass def symmetric_difference(self, *args, **kwargs): # real signature unknown #对称差集（取双方对象中都不重复的元素），创建新集合 s = set((1,2,6)) t = set((1,2,3,4,5)) a = s.symmetric_difference(t)#返回一个新的set包含s和t中不重复的元素 print(a) {3, 4, 5, 6} """ Return the symmetric difference of two sets as a new set. (i.e. all elements that are in exactly one of the sets.) """ pass def symmetric_difference_update(self, *args, **kwargs): # real signature unknown #差集，改变原来 s = set((1,2,3,4)) t = set((1,2,3,4,5)) s.symmetric_difference_update(t)#返回含义set “t”和set “s”中有而不是两者都有的元素的set “s” print(s) {5} """ Update a set with the symmetric difference of itself and another. """ pass def union(self, *args, **kwargs): # real signature unknown #并集 s = set((1,2,3,4)) t = set((1,2,3,4,5)) a = s.union(t)#返回一个新的set包含s和t中的每一个元素 print(a) {1, 2, 3, 4, 5} """ Return the union of sets as a new set. (i.e. all elements that are in either set.) """ pass def update(self, *args, **kwargs): # real signature unknown #更新 s = set((1,2,3,4)) t = set((1,2,3,4,5)) t.update(s)#“t”中包含“s”中对象，则“t”返回原值 s.update(t)#“s”中未包含“t”中对象，则s返回增加t中元素的set“ print(t) {1, 2, 3, 4, 5} print(s) {1, 2, 3, 4, 5} """ Update a set with the union of itself and others. """ pass def __and__(self, *args, **kwargs): # real signature unknown """ Return self&value. """ pass def __contains__(self, y): # real signature unknown; restored from __doc__ """ x.__contains__(y) <==> y in x. """ pass def __eq__(self, *args, **kwargs): # real signature unknown """ Return self==value. """ pass def __getattribute__(self, *args, **kwargs): # real signature unknown """ Return getattr(self, name). """ pass def __ge__(self, *args, **kwargs): # real signature unknown """ Return self>=value. """ pass def __gt__(self, *args, **kwargs): # real signature unknown """ Return self>value. """ pass def __iand__(self, *args, **kwargs): # real signature unknown """ Return self&=value. """ pass def __init__(self, seq=()): # known special case of set.__init__ """ set() -> new empty set object set(iterable) -> new set object Build an unordered collection of unique elements. # (copied from class doc) """ pass def __ior__(self, *args, **kwargs): # real signature unknown """ Return self|=value. """ pass def __isub__(self, *args, **kwargs): # real signature unknown """ Return self-=value. """ pass def __iter__(self, *args, **kwargs): # real signature unknown """ Implement iter(self). """ pass def __ixor__(self, *args, **kwargs): # real signature unknown """ Return self^=value. """ pass def __len__(self, *args, **kwargs): # real signature unknown """ Return len(self). """ pass def __le__(self, *args, **kwargs): # real signature unknown """ Return self<=value. """ pass def __lt__(self, *args, **kwargs): # real signature unknown """ Return self<value. """ pass @staticmethod # known case of __new__ def __new__(*args, **kwargs): # real signature unknown """ Create and return a new object. See help(type) for accurate signature. """ pass def __ne__(self, *args, **kwargs): # real signature unknown """ Return self!=value. """ pass def __or__(self, *args, **kwargs): # real signature unknown """ Return self|value. """ pass def __rand__(self, *args, **kwargs): # real signature unknown """ Return value&self. """ pass def __reduce__(self, *args, **kwargs): # real signature unknown """ Return state information for pickling. """ pass def __repr__(self, *args, **kwargs): # real signature unknown """ Return repr(self). """ pass def __ror__(self, *args, **kwargs): # real signature unknown """ Return value|self. """ pass def __rsub__(self, *args, **kwargs): # real signature unknown """ Return value-self. """ pass def __rxor__(self, *args, **kwargs): # real signature unknown """ Return value^self. """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ S.__sizeof__() -> size of S in memory, in bytes """ pass def __sub__(self, *args, **kwargs): # real signature unknown """ Return self-value. """ pass def __xor__(self, *args, **kwargs): # real signature unknown """ Return self^value. """ pass __hash__ = None
collections系列
计数器（Counter）#对字典进行加工
class Counter(dict): '''Dict subclass for counting hashable items. Sometimes called a bag or multiset. Elements are stored as dictionary keys and their counts are stored as dictionary values. >>> c = Counter('abcdeabcdabcaba') # count elements from a string >>> c.most_common(3) # three most common elements [('a', 5), ('b', 4), ('c', 3)] >>> sorted(c) # list all unique elements ['a', 'b', 'c', 'd', 'e'] >>> ''.join(sorted(c.elements())) # list elements with repetitions 'aaaaabbbbcccdde' >>> sum(c.values()) # total of all counts 15 >>> c['a'] # count of letter 'a' 5 >>> for elem in 'shazam': # update counts from an iterable ... c[elem] += 1 # by adding 1 to each element's count >>> c['a'] # now there are seven 'a' 7 >>> del c['b'] # remove all 'b' >>> c['b'] # now there are zero 'b' 0 >>> d = Counter('simsalabim') # make another counter >>> c.update(d) # add in the second counter >>> c['a'] # now there are nine 'a' 9 >>> c.clear() # empty the counter >>> c Counter() Note: If a count is set to zero or reduced to zero, it will remain in the counter until the entry is deleted or the counter is cleared: >>> c = Counter('aaabbc') >>> c['b'] -= 2 # reduce the count of 'b' by two >>> c.most_common() # 'b' is still in, but its count is zero [('a', 3), ('c', 1), ('b', 0)] ''' # References: # http://en.wikipedia.org/wiki/Multiset # http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html # http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm # http://code.activestate.com/recipes/259174/ # Knuth, TAOCP Vol. II section 4.6.3 def __init__(*args, **kwds): '''Create a new, empty Counter object. And if given, count elements from an input iterable. Or, initialize the count from another mapping of elements to their counts. >>> c = Counter() # a new, empty counter >>> c = Counter('gallahad') # a new counter from an iterable >>> c = Counter({'a': 4, 'b': 2}) # a new counter from a mapping >>> c = Counter(a=4, b=2) # a new counter from keyword args ''' if not args: raise TypeError("descriptor '__init__' of 'Counter' object " "needs an argument") self, *args = args if len(args) > 1: raise TypeError('expected at most 1 arguments, got %d' % len(args)) super(Counter, self).__init__() self.update(*args, **kwds) def __missing__(self, key): 'The count of elements not in the Counter is zero.' # Needed so that self[missing_item] does not raise KeyError return 0 def most_common(self, n=None): '''List the n most common elements and their counts from the most common to the least. If n is None, then list all element counts. >>> Counter('abcdeabcdabcaba').most_common(3) [('a', 5), ('b', 4), ('c', 3)] ''' # Emulate Bag.sortedByCount from Smalltalk if n is None: return sorted(self.items(), key=_itemgetter(1), reverse=True) return _heapq.nlargest(n, self.items(), key=_itemgetter(1)) def elements(self): '''Iterator over elements repeating each as many times as its count. #列出所有元素 >>> c = Counter('ABCABC') >>> sorted(c.elements()) ['A', 'A', 'B', 'B', 'C', 'C'] # Knuth's example for prime factors of 1836: 2**2 * 3**3 * 17**1 >>> prime_factors = Counter({2: 2, 3: 3, 17: 1}) >>> product = 1 >>> for factor in prime_factors.elements(): # loop over factors ... product *= factor # and multiply them >>> product 1836 Note, if an element's count has been set to zero or is a negative number, elements() will ignore it. ''' # Emulate Bag.do from Smalltalk and Multiset.begin from C++. return _chain.from_iterable(_starmap(_repeat, self.items())) # Override dict methods where necessary @classmethod def fromkeys(cls, iterable, v=None): # There is no equivalent method for counters because setting v=1 # means that no element can have a count greater than one. raise NotImplementedError( 'Counter.fromkeys() is undefined. Use Counter(iterable) instead.') def update(*args, **kwds): #更新数据 >>> a = collections.Counter(["11","22","33"]) a.update(["alex"]) >>> print(a) Counter({'11': 1, '33': 1, '22': 1, 'alex': 1}) '''Like dict.update() but add counts instead of replacing them. Source can be an iterable, a dictionary, or another Counter instance. >>> c = Counter('which') >>> c.update('witch') # add elements from another iterable >>> d = Counter('watch') >>> c.update(d) # add elements from another counter >>> c['h'] # four 'h' in which, witch, and watch 4 ''' # The regular dict.update() operation makes no sense here because the # replace behavior results in the some of original untouched counts # being mixed-in with all of the other counts for a mismash that # doesn't have a straight-forward interpretation in most counting # contexts. Instead, we implement straight-addition. Both the inputs # and outputs are allowed to contain zero and negative counts. if not args: raise TypeError("descriptor 'update' of 'Counter' object " "needs an argument") self, *args = args if len(args) > 1: raise TypeError('expected at most 1 arguments, got %d' % len(args)) iterable = args[0] if args else None if iterable is not None: if isinstance(iterable, Mapping): if self: self_get = self.get for elem, count in iterable.items(): self[elem] = count + self_get(elem, 0) else: super(Counter, self).update(iterable) # fast path when counter is empty else: _count_elements(self, iterable) if kwds: self.update(kwds) def subtract(*args, **kwds): #删除 '''Like dict.update() but subtracts counts instead of replacing them. Counts can be reduced below zero. Both the inputs and outputs are allowed to contain zero and negative counts. Source can be an iterable, a dictionary, or another Counter instance. >>> c = Counter('which') >>> c.subtract('witch') # subtract elements from another iterable >>> c.subtract(Counter('watch')) # subtract elements from another counter >>> c['h'] # 2 in which, minus 1 in witch, minus 1 in watch 0 >>> c['w'] # 1 in which, minus 1 in witch, minus 1 in watch -1 ''' if not args: raise TypeError("descriptor 'subtract' of 'Counter' object " "needs an argument") self, *args = args if len(args) > 1: raise TypeError('expected at most 1 arguments, got %d' % len(args)) iterable = args[0] if args else None if iterable is not None: self_get = self.get if isinstance(iterable, Mapping): for elem, count in iterable.items(): self[elem] = self_get(elem, 0) - count else: for elem in iterable: self[elem] = self_get(elem, 0) - 1 if kwds: self.subtract(kwds) def copy(self): 'Return a shallow copy.' return self.__class__(self) def __reduce__(self): return self.__class__, (dict(self),) def __delitem__(self, elem): 'Like dict.__delitem__() but does not raise KeyError for missing values.' if elem in self: super().__delitem__(elem) def __repr__(self): if not self: return '%s()' % self.__class__.__name__ try: items = ', '.join(map('%r: %r'.__mod__, self.most_common())) return '%s({%s})' % (self.__class__.__name__, items) except TypeError: # handle case where values are not orderable return '{0}({1!r})'.format(self.__class__.__name__, dict(self)) # Multiset-style mathematical operations discussed in: # Knuth TAOCP Volume II section 4.6.3 exercise 19 # and at http://en.wikipedia.org/wiki/Multiset # # Outputs guaranteed to only include positive counts. # # To strip negative and zero counts, add-in an empty counter: # c += Counter() def __add__(self, other): '''Add counts from two counters. >>> Counter('abbb') + Counter('bcc') Counter({'b': 4, 'c': 2, 'a': 1}) ''' if not isinstance(other, Counter): return NotImplemented result = Counter() for elem, count in self.items(): newcount = count + other[elem] if newcount > 0: result[elem] = newcount for elem, count in other.items(): if elem not in self and count > 0: result[elem] = count return result def __sub__(self, other): ''' Subtract count, but keep only results with positive counts. >>> Counter('abbbc') - Counter('bccd') Counter({'b': 2, 'a': 1}) ''' if not isinstance(other, Counter): return NotImplemented result = Counter() for elem, count in self.items(): newcount = count - other[elem] if newcount > 0: result[elem] = newcount for elem, count in other.items(): if elem not in self and count < 0: result[elem] = 0 - count return result def __or__(self, other): '''Union is the maximum of value in either of the input counters. >>> Counter('abbb') | Counter('bcc') Counter({'b': 3, 'c': 2, 'a': 1}) ''' if not isinstance(other, Counter): return NotImplemented result = Counter() for elem, count in self.items(): other_count = other[elem] newcount = other_count if count < other_count else count if newcount > 0: result[elem] = newcount for elem, count in other.items(): if elem not in self and count > 0: result[elem] = count return result def __and__(self, other): ''' Intersection is the minimum of corresponding counts. >>> Counter('abbb') & Counter('bcc') Counter({'b': 1}) ''' if not isinstance(other, Counter): return NotImplemented result = Counter() for elem, count in self.items(): other_count = other[elem] newcount = count if count < other_count else other_count if newcount > 0: result[elem] = newcount return result def __pos__(self): 'Adds an empty counter, effectively stripping negative and zero counts' result = Counter() for elem, count in self.items(): if count > 0: result[elem] = count return result def __neg__(self): '''Subtracts from an empty counter. Strips positive and zero counts, and flips the sign on negative counts. ''' result = Counter() for elem, count in self.items(): if count < 0: result[elem] = 0 - count return result def _keep_positive(self): '''Internal method to strip elements with a negative or zero count''' nonpositive = [elem for elem, count in self.items() if not count > 0] for elem in nonpositive: del self[elem] return self def __iadd__(self, other): '''Inplace add from another counter, keeping only positive counts. >>> c = Counter('abbb') >>> c += Counter('bcc') >>> c Counter({'b': 4, 'c': 2, 'a': 1}) ''' for elem, count in other.items(): self[elem] += count return self._keep_positive() def __isub__(self, other): '''Inplace subtract counter, but keep only results with positive counts. >>> c = Counter('abbbc') >>> c -= Counter('bccd') >>> c Counter({'b': 2, 'a': 1}) ''' for elem, count in other.items(): self[elem] -= count return self._keep_positive() def __ior__(self, other): '''Inplace union is the maximum of value from either counter. >>> c = Counter('abbb') >>> c |= Counter('bcc') >>> c Counter({'b': 3, 'c': 2, 'a': 1}) ''' for elem, other_count in other.items(): count = self[elem] if other_count > count: self[elem] = other_count return self._keep_positive() def __iand__(self, other): '''Inplace intersection is the minimum of corresponding counts. >>> c = Counter('abbb') >>> c &= Counter('bcc') >>> c Counter({'b': 1}) ''' for elem, count in self.items(): other_count = other[elem] if other_count < count: self[elem] = other_count return self._keep_positive()
有序字典（OrderedDict）
class OrderedDict(dict): """ Dictionary that remembers insertion order """ def clear(self): # real signature unknown; restored from __doc__ """ od.clear() -> None. Remove all items from od. """ pass def copy(self): # real signature unknown; restored from __doc__ """ od.copy() -> a shallow copy of od """ pass @classmethod def fromkeys(cls, S, v=None): # real signature unknown; restored from __doc__ """ OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S. If not specified, the value defaults to None. """ pass def items(self, *args, **kwargs): # real signature unknown pass def keys(self, *args, **kwargs): # real signature unknown pass def move_to_end(self, *args, **kwargs): # real signature unknown #指定一个值放到最后 """ Move an existing element to the end (or beginning if last==False). Raises KeyError if the element does not exist. When last=True, acts like a fast version of self[key]=self.pop(key). """ pass def pop(self, k, d=None): # real signature unknown; restored from __doc__ """ od.pop(k[,d]) -> v, remove specified key and return the corresponding value. If key is not found, d is returned if given, otherwise KeyError is raised. """ pass def popitem(self): # real signature unknown; restored from __doc__ """ od.popitem() -> (k, v), return and remove a (key, value) pair. Pairs are returned in LIFO order if last is true or FIFO order if false. """ pass def setdefault(self, k, d=None): # real signature unknown; restored from __doc__ """ od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od """ pass def update(self, *args, **kwargs): # real signature unknown pass def values(self, *args, **kwargs): # real signature unknown pass def __delitem__(self, *args, **kwargs): # real signature unknown """ Delete self[key]. """ pass def __eq__(self, *args, **kwargs): # real signature unknown """ Return self==value. """ pass def __ge__(self, *args, **kwargs): # real signature unknown """ Return self>=value. """ pass def __gt__(self, *args, **kwargs): # real signature unknown """ Return self>value. """ pass def __init__(self, *args, **kwargs): # real signature unknown pass def __iter__(self, *args, **kwargs): # real signature unknown """ Implement iter(self). """ pass def __le__(self, *args, **kwargs): # real signature unknown """ Return self<=value. """ pass def __lt__(self, *args, **kwargs): # real signature unknown """ Return self<value. """ pass @staticmethod # known case of __new__ def __new__(*args, **kwargs): # real signature unknown """ Create and return a new object. See help(type) for accurate signature. """ pass def __ne__(self, *args, **kwargs): # real signature unknown """ Return self!=value. """ pass def __reduce__(self, *args, **kwargs): # real signature unknown """ Return state information for pickling """ pass def __repr__(self, *args, **kwargs): # real signature unknown """ Return repr(self). """ pass def __reversed__(self): # real signature unknown; restored from __doc__ """ od.__reversed__() <==> reversed(od) """ pass def __setitem__(self, *args, **kwargs): # real signature unknown """ Set self[key] to value. """ pass def __sizeof__(self, *args, **kwargs): # real signature unknown pass __dict__ = None # (!) real value is '' __hash__ = None
默认字典（defaultdict）
#!/usr/bin/env python3 import collections li = [11,22,33,44,55,66,77,88,99] my_dict = collections.defaultdict(list)#通过默认字典，设置my_dict为空列表 for i in li: if i >66: my_dict["k1"].append(i) else: my_dict["k2"].append(i) print(my_dict["k1"],my_dict["k2"]) [77, 88, 99] [11, 22, 33, 44, 55, 66]
可命名元组（namedtuple）
#!/usr/bin/env python3 import collections MytupleClass = collections.namedtuple("MytupleClass",["x","y","z"])#通过自定义类创建别名 a = MytupleClass(11,22,33)#通过自定义类给定元素赋值给“a” print(a.x,a.y,a.z)#打印出对应别名的值 11 22 33
双向队列（deque）
class deque(object): """ deque([iterable[, maxlen]]) --> deque object A list-like sequence optimized for data accesses near its endpoints. """ def append(self, *args, **kwargs): # real signature unknown #添加元素 """ Add an element to the right side of the deque. """ pass def appendleft(self, *args, **kwargs): # real signature unknown #在左边添加元素 """ Add an element to the left side of the deque. """ pass def clear(self, *args, **kwargs): # real signature unknown #清空元素 """ Remove all elements from the deque. """ pass def copy(self, *args, **kwargs): # real signature unknown """ Return a shallow copy of a deque. """ pass def count(self, value): # real signature unknown; restored from __doc__ #统计元素出现的次数 """ D.count(value) -> integer -- return number of occurrences of value """ return 0 def extend(self, *args, **kwargs): # real signature unknown #扩展（添加多个数据） """ Extend the right side of the deque with elements from the iterable """ pass def extendleft(self, *args, **kwargs): # real signature unknown #在左边扩展（添加多个数据） """ Extend the left side of the deque with elements from the iterable """ pass def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ #索引 """ D.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__ #插入 """ D.insert(index, object) -- insert object before index """ pass def pop(self, *args, **kwargs): # real signature unknown #移除并拿到 """ Remove and return the rightmost element. """ pass def popleft(self, *args, **kwargs): # real signature unknown #从左边移除并拿到 """ Remove and return the leftmost element. """ pass def remove(self, value): # real signature unknown; restored from __doc__ #删除指定值 """ D.remove(value) -- remove first occurrence of value. """ pass def reverse(self): # real signature unknown; restored from __doc__ #反转 """ D.reverse() -- reverse *IN PLACE* """ pass def rotate(self, *args, **kwargs): # real signature unknown #旋转 d = collections.deque(["1","10","1","a","f","dg"]) print(d) d.rotate(3)#按照数字进行旋转，每次拿最后一个元素放到最前面 print(d) deque(['1', '10', '1', 'a', 'f', 'dg']) deque(['a', 'f', 'dg', '1', '10', '1']) """ Rotate the deque n steps to the right (default n=1). If n is negative, rotates left. """ pass def __add__(self, *args, **kwargs): # real signature unknown """ Return self+value. """ pass def __bool__(self, *args, **kwargs): # real signature unknown """ self != 0 """ pass def __contains__(self, *args, **kwargs): # real signature unknown """ Return key in self. """ pass def __copy__(self, *args, **kwargs): # real signature unknown """ Return a shallow copy of a deque. """ pass def __delitem__(self, *args, **kwargs): # real signature unknown """ Delete self[key]. """ pass def __eq__(self, *args, **kwargs): # real signature unknown """ Return self==value. """ pass def __getattribute__(self, *args, **kwargs): # real signature unknown """ Return getattr(self, name). """ pass def __getitem__(self, *args, **kwargs): # real signature unknown """ Return self[key]. """ pass def __ge__(self, *args, **kwargs): # real signature unknown """ Return self>=value. """ pass def __gt__(self, *args, **kwargs): # real signature unknown """ Return self>value. """ pass def __iadd__(self, *args, **kwargs): # real signature unknown """ Implement self+=value. """ pass def __imul__(self, *args, **kwargs): # real signature unknown """ Implement self*=value. """ pass def __init__(self, iterable=(), maxlen=None): # known case of _collections.deque.__init__ """ deque([iterable[, maxlen]]) --> deque object A list-like sequence optimized for data accesses near its endpoints. # (copied from class doc) """ pass def __iter__(self, *args, **kwargs): # real signature unknown """ Implement iter(self). """ pass def __len__(self, *args, **kwargs): # real signature unknown """ Return len(self). """ pass def __le__(self, *args, **kwargs): # real signature unknown """ Return self<=value. """ pass def __lt__(self, *args, **kwargs): # real signature unknown """ Return self<value. """ pass def __mul__(self, *args, **kwargs): # real signature unknown """ Return self*value.n """ pass @staticmethod # known case of __new__ def __new__(*args, **kwargs): # real signature unknown """ Create and return a new object. See help(type) for accurate signature. """ pass def __ne__(self, *args, **kwargs): # real signature unknown """ Return self!=value. """ pass def __reduce__(self, *args, **kwargs): # real signature unknown """ Return state information for pickling. """ pass def __repr__(self, *args, **kwargs): # real signature unknown """ Return repr(self). """ pass def __reversed__(self): # real signature unknown; restored from __doc__ """ D.__reversed__() -- return a reverse iterator over the deque """ pass def __rmul__(self, *args, **kwargs): # real signature unknown """ Return self*value. """ pass def __setitem__(self, *args, **kwargs): # real signature unknown """ Set self[key] to value. """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ D.__sizeof__() -- size of D in memory, in bytes """ pass maxlen = property(lambda self: object(), lambda self, v: None, lambda self: None) # default """maximum size of a deque or None if unbounded""" __hash__ = None
单向队列
#!/usr/bin/env python3 import queue q = queue.Queue()#单向队列 q.put("123","fds")#添加一条 q.put("45")#添加一条 print(q.qsize())#统计队列中有多少数据 print(q.get())#取出一条数据（采用先进先出原则）
class Queue: '''Create a queue object with a given maximum size. If maxsize is <= 0, the queue size is infinite. ''' def __init__(self, maxsize=0): self.maxsize = maxsize self._init(maxsize) # mutex must be held whenever the queue is mutating. All methods # that acquire mutex must release it before returning. mutex # is shared between the three conditions, so acquiring and # releasing the conditions also acquires and releases mutex. self.mutex = threading.Lock() # Notify not_empty whenever an item is added to the queue; a # thread waiting to get is notified then. self.not_empty = threading.Condition(self.mutex) # Notify not_full whenever an item is removed from the queue; # a thread waiting to put is notified then. self.not_full = threading.Condition(self.mutex) # Notify all_tasks_done whenever the number of unfinished tasks # drops to zero; thread waiting to join() is notified to resume self.all_tasks_done = threading.Condition(self.mutex) self.unfinished_tasks = 0 def task_done(self): '''Indicate that a formerly enqueued task is complete. Used by Queue consumer threads. For each get() used to fetch a task, a subsequent call to task_done() tells the queue that the processing on the task is complete. If a join() is currently blocking, it will resume when all items have been processed (meaning that a task_done() call was received for every item that had been put() into the queue). Raises a ValueError if called more times than there were items placed in the queue. ''' with self.all_tasks_done: unfinished = self.unfinished_tasks - 1 if unfinished <= 0: if unfinished < 0: raise ValueError('task_done() called too many times') self.all_tasks_done.notify_all() self.unfinished_tasks = unfinished def join(self): '''Blocks until all items in the Queue have been gotten and processed. The count of unfinished tasks goes up whenever an item is added to the queue. The count goes down whenever a consumer thread calls task_done() to indicate the item was retrieved and all work on it is complete. When the count of unfinished tasks drops to zero, join() unblocks. ''' with self.all_tasks_done: while self.unfinished_tasks: self.all_tasks_done.wait() def qsize(self): #查看队列中元素的个数 '''Return the approximate size of the queue (not reliable!).''' with self.mutex: return self._qsize() def empty(self): #和clear一样 '''Return True if the queue is empty, False otherwise (not reliable!). This method is likely to be removed at some point. Use qsize() == 0 as a direct substitute, but be aware that either approach risks a race condition where a queue can grow before the result of empty() or qsize() can be used. To create code that needs to wait for all queued tasks to be completed, the preferred technique is to use the join() method. ''' with self.mutex: return not self._qsize() def full(self): #是否填满 '''Return True if the queue is full, False otherwise (not reliable!). This method is likely to be removed at some point. Use qsize() >= n as a direct substitute, but be aware that either approach risks a race condition where a queue can shrink before the result of full() or qsize() can be used. ''' with self.mutex: return 0 < self.maxsize <= self._qsize() def put(self, item, block=True, timeout=None): #插入数据 '''Put an item into the queue. If optional args 'block' is true and 'timeout' is None (the default), block if necessary until a free slot is available. If 'timeout' is a non-negative number, it blocks at most 'timeout' seconds and raises the Full exception if no free slot was available within that time. Otherwise ('block' is false), put an item on the queue if a free slot is immediately available, else raise the Full exception ('timeout' is ignored in that case). ''' with self.not_full: if self.maxsize > 0: if not block: if self._qsize() >= self.maxsize: raise Full elif timeout is None: while self._qsize() >= self.maxsize: self.not_full.wait() elif timeout < 0: raise ValueError("'timeout' must be a non-negative number") else: endtime = time() + timeout while self._qsize() >= self.maxsize: remaining = endtime - time() if remaining <= 0.0: raise Full self.not_full.wait(remaining) self._put(item) self.unfinished_tasks += 1 self.not_empty.notify() def get(self, block=True, timeout=None): #取数据 '''Remove and return an item from the queue. If optional args 'block' is true and 'timeout' is None (the default), block if necessary until an item is available. If 'timeout' is a non-negative number, it blocks at most 'timeout' seconds and raises the Empty exception if no item was available within that time. Otherwise ('block' is false), return an item if one is immediately available, else raise the Empty exception ('timeout' is ignored in that case). ''' with self.not_empty: if not block: if not self._qsize(): raise Empty elif timeout is None: while not self._qsize(): self.not_empty.wait() elif timeout < 0: raise ValueError("'timeout' must be a non-negative number") else: endtime = time() + timeout while not self._qsize(): remaining = endtime - time() if remaining <= 0.0: raise Empty self.not_empty.wait(remaining) item = self._get() self.not_full.notify() return item def put_nowait(self, item): '''Put an item into the queue without blocking. Only enqueue the item if a free slot is immediately available. Otherwise raise the Full exception. ''' return self.put(item, block=False) def get_nowait(self): '''Remove and return an item from the queue without blocking. Only get an item if one is immediately available. Otherwise raise the Empty exception. ''' return self.get(block=False) # Override these methods to implement other queue organizations # (e.g. stack or priority queue). # These will only be called with appropriate locks held # Initialize the queue representation def _init(self, maxsize): self.queue = deque() def _qsize(self): return len(self.queue) # Put a new item in the queue def _put(self, item): self.queue.append(item) # Get an item from the queue def _get(self): return self.queue.popleft()
浅拷贝
dic = {"cpu":[80],"mom":[80],"disk":[80]}
print("old",dic)
new_dic = copy.copy(dic) #浅拷贝，会改变原数据
new_dic["cpu"][0] = 50
print(dic)
print(new_dic)
深拷贝
dic = {"cpu":80,"mom":80,"disk":80}
print("old",dic)
new_dic = copy.deepcopy(dic)#深拷贝则修改你要改的值
new_dic["cpu"] = 50
print(dic)
print(new_dic)
函数
def show():#def是定义函数的关键字，函数名后必须更括号 print("123") return"ss" #返回值，不写return返回None a = show()#函数名加扩号，表示执行该函数,可将返回值赋值给变量 print(a) 123 ss #一个参数 def show(a):#形参 print(a) show(123)#实参，把参数赋值给a 123 #多个参数 def show(a,b,c):#可指定多形参 print(a,b,c) show(123,456,789)#实参数量必须和形参一致（一一对应） 123 456 789 def show(args): print(args) show([123,456,789]) [123, 456, 789] #默认参数 def show(a,b=123):#默认参数须先赋值，只能写到最后(a后面，并且后面也不能跟形参) print(a,b) show(123,456) 123 456 #指定参数 def show(a,b,c): print(a,b,c) show(c=789,a=123,b=456,) 123 456 789 #动态参数 def show(*args):#单星转成元组 print(args,type(args)) show([123,456,789]) ([123, 456, 789],) <class 'tuple'> def show(**kwargs):#双星转成字典 print(kwargs,type(kwargs)) show(a=123,b=456) {'b': 456, 'a': 123} <class 'dict'> def show(*a,**b):#混合模式下，必须单星在前 print(a,type(a)) print(b,type(b)) show(123,456,abc = 123,cde = 456)#不能混传，如（abc = 123,123）必须根据星来使用 (123, 456) <class 'tuple'> {'cde': 456, 'abc': 123} <class 'dict'> def show(*a,**b): print(a,type(a)) print(b,type(b)) l =(123,456) d ={'abc':123,'cde':456} show(*l,**d)#把值传到指定位置 (123, 456) <class 'tuple'> {'abc': 123, 'cde': 456} <class 'dict'> #字符格式化 c = ["name","abc"] d = {"a":"name","b":"abc"} s = "{0} is {1}".format(*c) s1 = "{a} is {b}".format(**d) print(s,s1)
Lambda表达式
def func(a,b): return a*b ret = func(4,5) print(ret) #lambda表达式,同以上函数 func = lambda a,b: a*b ret = func(4,5) print(ret)
内置函数#只写了部分
all()#传入的序列所有的值都真，才为真 all(["",[],(),{},None])#为假 any()#只有一个真都为真 any(["",[],(),{},None,1,])#只有一个真都为真 ascii(8) 等同 (int.__repr__(8)) bin()#二进制 bytearray("方法",encoding="utf-8")#转成字节数组 bytes("方法",encoding="utf-8")#转成字符 callable()#是否可执行 chr()#数字转ascii字符 chr(65) ord()#ascii转数字 ord("A") enumerate()#生成序列 li = ["a","b","c"] for i,item in enumerate(li,1): print(i,item) eval("6*8")#将字符串运算转换为数字运算
文件操作
文件句柄 = open("文件路径","模式")
打开文件的模式有：
r,只读模式（默认）
w,只写模式（不可读，不存在创建文件，存在删除内容）
a,追加模式（可读，不存在创建文件，存在追加内容）
“+”表示可以同时读写
r+,可读写文件（可读，可写，可追加）
w+,写读
a+,同a
“U”表示在读取时，可以将\r \n \r\n自动转换成\n（与r或r+模式同使用）
ru
r+U
“b”表示处理二进制文件（如：FTP发送上传ISO镜像文件，Linux可忽略，Windows处理二进制文件时需标注）
rb
wb
ab
