#coding=utf8 __author__ = 'libai' #1,字典key和value互换 #方法一 dict={ "name":"baoshizhen","age":12} new_dict={} for i,j in dict.items(): new_dict[j]=i print new_dict #方法二 new_dict2={} j=0 for i in dict.values(): new_dict2[i]=dict.keys()[j] j+=1 print new_dict2 #方法三(一句话) print eval("{"+",".join([":".join(i) for i in map(lambda x:reversed(x.split(":")),str(dict)[1:-1].split(","))])+"}") #2,找出列表中包含多少的列表元素 #方法一: a=[1,[2],[3],'a'] sum=0 for i in a: if isinstance(i,list): sum+=1 print sum #方法二 print len(filter(lambda x:isinstance(x,list),a)) #3,删除列表中的元素4 text_3=[1,4,4,4,4,5,6] #方法一 number_4=text_3.count(4) for i in range(number_4): text_3.remove(4) print text_3 #方法二 text_3_2=[1,4,4,4,4,5,6] print filter(lambda x:x!=4,text_3_2) #4,将[1, 2, 5, 6]转换成‘1256’ #方法一 print ''.join(map(lambda x:str(x),[1,2,5,6])) #方法二 result_4='' for i in [1,2,5,6]: result_4+=str(i) print result_4 #5,去重复 text_5=[1,1,2,2,3,3] #方法一 print set(text_5) #方法二 new_text_5=[] for i in text_5: if i not in new_text_5: new_text_5.append(i) print new_text_5 #方法三 dict_text_5={} for i in text_5: dict_text_5[i]=1 print dict_text_5.keys() #方法四: text_5=[1,1,2,2,3,3] for i in text_5: if text_5.count(i)>1: text_5.remove(i) print text_5 #6,找出boy是第几个单词 text_6='I am a boy' #方法一 print text_6.split(' ').index('boy')+1 #方法二 list_6=text_6.split(' ') for i in range(len(list_6)): if list_6[i]=='boy': print i+1 break
python之列表练习
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