python基礎2—集合框架
阿新 • • 發佈:2018-01-22
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詳細的,比較深入的,比如集合容量初始化,擴容, 目前只是學到基礎的用法。
------------------list-------------------- # li = [1,2,3, ‘456‘, [1,2,3], {1:‘one‘, 2:‘two‘}] print(type(list)) print(type(li)) # list print(li[0]) print(li[-1]) print(li[-2]) # find index of element print(li.index(‘456‘)) print(li.index([1,2,3]))print(li.index(-1) del(li[-1]) #delete element del(list[index]) # add element l_a = [1, 2, 3] l_a.append(4) l_a.append(5) l_b = [6, 7, 8] l_a.extend(l_b) # extend會展開再一個一個的添加 l_a.append(l_b) # append 會將其視為一個對象 print(l_a) # will be [1, 2, 3, 4, 5, 6, 7, 8] l_a = [] if not l_a:print(‘Empty‘) # empty 有內存分配 pass if l_a is None: print(‘None‘) # None 無內存分配 pass # for loop for i in li: print(i) pass for i in range(len(li)): print(i) pass # ------------------dict-------------------- # d = {‘a‘:1, ‘b‘:2, 1:‘one‘, 2:‘two‘, 3:[1,2,3]} print(type(dict))print(type(d)) print(d) # # access element print(d[‘a‘]) print(d[1]) print(d[3]) # key is exist print(‘two‘ in d) print(3 in d) del(d[3]) # del(dict[key]) d[3] = [1, 2, 3, 4] # add or update element when key=3 d[‘a‘] = ‘1234‘ # add or update element when key=‘a‘ print(len(d)) # ------------------set-------------------- # s_a = set([1, 2, 2, 3, 4, 5, 6]) s_b = set([4, 5, 6, 7, 8, 9]) print(s_a) print(s_b) # element is exist print(5 in s_a) print(10 in s_b) # 並集 A | B => A.unio(B) print(s_a | s_b) print(s_a.union(s_b)) # 交集 A & B => A.intersection(B) print(s_a & s_b) print(s_a.intersection(s_b)) # 差集 A - B = A - (A & B) => A.difference(B) print(s_a - s_b) print(s_a.difference(s_b)) # 對稱差 (A | B ) - (A & B) => A.symmetric_difference(B) print(s_a ^ s_b) print(s_a.symmetric_difference(s_b)) # add or modify element s_a.add(‘x‘) s_a.update([4, 5, 60, 70]) # add array to set print(s_a) s_a.remove(70) print(s_a) print(len(s_a)) for x in s_a: print(x) pass
python基礎2—集合框架