Python以其简洁的语法着称。本文主要用一行Python代码实现各种小需求，一起来感受一下Python的强大吧~hellopythonprint("hellopython")hellopython二进制转十进制int("01110",2)#2^3+2^2+214八进制转十进制int("140",8)96十六进制转十进制int("ac1",16)2753生成连续值列表list(range(9))[0,1,2,3,4,5,6,7,8]高斯求和一行代码求高斯求和sum(range(0,101))#range函数不包括1015050求奇偶数求和#除以2余数为0表示为偶数sum(iforiinrange(0,101)ifi%2==0)2550#除以2余数为0表示为奇数sum(iforiinrange(0,101)ifi%2!=0)2500nestedlistsmerge列表合并成一个大列表list4=[[1,2,3],[4,5,6],[7,8,9]]#定义一个列表list(itemforlist5inlist4foriteminlist5)#从大到小[1,2,3,4,5,6,7,8,9]listmergea=[1,2,3]b=[4,5,6]a.extend(b)a[1,2,3,4,5,6]反向列表list6=[1,2,3,4,5,6,7]list6[::-1][7,6,5,4,3,2,1]列表解包h,*i,j=[1,2,3,4,5]print(h)print(i)print(j)1[2,3,4]5list去重通过将list转成set，利用set的去重特性，再转成listlist7=[1,2,3,4,3,2,3,3]list(set(list7))[1,2,3,4]listfilterfilter函数的两个参数：指定某个函数要执行的可迭代对象，每个对象执行上一个函数list(filter(lambdax:x%3==0,[1,3,6,7,9,10]))#找到3[3,6,9]的倍数listcomprehension[numberfornumberinrange(0,11)]#[][0,1,2,3,4,5,6,7,8,9,10]setderivation{numberfornumberinrange(0,11)}#{}{0,1,2,3,4,5,6,7,8,9,10}合并集s1={1,2,3}s2={4,5,6}s1.update(s2)s1{1,2,3,4,5,6}字典推导{i:i**3foriinrange(0,5)}#i**3表示i的立方体{0:0,1:1,2:8,3:27,4:64}合并字典d1={"name1":"xiaoming","age1":19}d2={"name2":"xiaoming","age2":28}d1.update(d2)d1{'name1':'xiaoming','age1':19,'name2':'xiaoming','age2':28}factorialimportmath#需要使用第三个-partyLibrarymath.factorial(6)#6*5*4*3*2*1720矩阵转置矩阵转置是实现矩阵行列转换list1=[[1,4,7],[2,5,8],[3,6,9]]#定义嵌套列表list(list(x)forxinzip(*list1))#列表函数实现[[1,2,3],[4,5,6],[7,8,9]][list(x)forxinzip(*list1)]#[]符号实现[[1,2,3],[4,5,6],[7,8,9]]forxinzip(*list1):print(list(x))[1,2,3][4,5,6][7,8,9]if-for#找到3[numberfor范围内的数字(0,20)ifnumber%3==0][0,3,6,9,12,15,18]if-elseprint("偶数")if8%2==0else("奇数")偶数print("偶数")if9%2==0elseprint("奇数")奇数quicksortlist2=[9,5,1,6,2,8]#定义一个列表sorted(list2)#默认升序[1,2,5,6,8,9]sorted(list2,reverse=True)#降序[9,8,6,5,2,1]list3=["ac","ab","bb","aa","bc","cd","ca"]排序（list3）['aa','ab','ac','bb','bc','ca','cd']首先我们按照首字母的ASCII排序，默认是升序；a是最小的当第一个字母相同时，将字符串按照第二个字母排序，变成字节"stringtobytes".encode()b'stringtobytes'得到26个字母importstringstring.ascii_letters#大小写'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'获取大写字母string.ascii_uppercase'ABCDEFGHIJKLMNOPQRSTUVWXYZ'获取小写字母string.ascii_lowercase'abcdefghijklmnopqrstuvwxyz'字符串大小写转换"Hello!MynameisPeter".lower()#Converttolowercase'hello!mynameispeter'#另一种转换为小写的方式"Hello!MynameisPeter".casefold()'hello!mynameispeter'"Hello!MynameisPeter".upper()#转换为全部大写'HELLO!MYNAMEISPETER'"Hello!MynameisPeter".title()#转换为大写'Hello!MyNameIsPeter'求最长字符串list7=["c","html","javascript","java"]max(list7,key=len)#key参数指定函数'javascript'max(list7)#默认'javascript'删除字符串中的数字"".join(list(filter(lambdax:x.isalpha(),"abcde12hk18")))'abcdehk'list(filter(lambdax:x.isalpha(),"abcde12hk18"))['a','b','c','d','e','h','k']stringsinthelistbecomenumericlist(map(int,["10","90","50"]))[10,90,50]stringsReverse"python"[::-1]'nohtyp'exchangevariablea,b=5,8#定义两个变量print("abeforeexchange:",a)print("bbeforeexchange:",b)Beforeexchangea:5Beforeexchangeb:8a,b=b,a#一行代码exchangeprint("afterexchangea:",a)print("afterexchangeb:",b)afterexchangea:8afterexchangeb:5data类型检查isinstance(5,int)#valueTrueisinstance("python",int)Falseisinstance("python",str)#stringTrueisinstance([1,3,6],list)#listTrueisinstanceDeedsequencefibo=lambdax:xifx<=1elsefibo(x-1)+fibo(x-2)fibo(10)55统计词频统计字符串"javascript".count("a")中单个字符出现的次数2"javascript".count("s")1"hello".count("l")2统计列表元素个数importpandasaspdlist10=[1,3,4,6,1,2,3,1,1,2,5,6,2]pd.value_counts(list10)142332624151dtype:int64统计个数stringelementsfromcollectionsimportCounterCounter("abcdeabcdabcaba")Counter({'a':5,'b':4,'c':3,'d':2,'e':1})统计最多的元素list10=[1,3,4,6,1,2,3,1,1,2,4,6,2]max(list10,key=list10.count)#元素1最多1min(list10,key=list10.count)#最少3个元素，只出现3个当前时间importtimetime.time()#时间戳形式1632501677.992713time.ctime()#标准形式'SatSep2500:41:182021'以上都是本次分享内容，如果你觉得文章还不错，欢迎关注公众号：Python编程学习圈，每日干货分享，发送“J”也可领取大量学习资料或前往编程学习网络学习更多编程技术知识。
