作业题
1 name = 'alex' 2 print(name.strip()) 3 print(name.startswith('a1')) 4 print(name.endswith('X')) 5 print(name.replace('1','p')) 6 print(name.split('1')) 7 print(name.upper()) 8 print(name.lower()) 9 print(name[1]) 10 print(name[0:3]) 11 print(name[-2:]) 12 print(name.find('e')) 13 print(name[0:len(name)-1])
上课笔记
# 字符串的操作 str1 = 'my name is xxx,my age is 18.'去 # 1.优先掌握的操作: # 按索引取值(正向取,反向取):只能取 print(str1[3]) # 2.切片(顾头不顾尾,步长) print(str1[3:7]) # 步长为2 print(str1[3:10:2]) # 3.长度len print(len(str1)) # 4.成员运算in和not in print('x' in str1) print('Y' in str1) # 5.切分split # 会根据split()括号中的规则去切分字符串,然后把每一个值追加到列表中 str2 = 'my name is xxx,my age is 18.' list2 = str2.split(' ') print(list2) # 6.移除空白strip #去除字符串左右两边的空格 str1 = 'my name is xxx,my age is 18.' print(str1) print(str1.strip()) # 7.循环 str2 = 'my name is xxx,my age is 18.' for line in str2: print(line) # print默认参数enf="\n" print(line,end=" ") #自定义参数 # 需要掌握的 str4 = 'my name is xxx,my age is 18.' str5 = 'my name is xxx,my age is 18.' # 1.strip,lstrip,rstrio # l去除左边的空格或者指定符号 # r去除右边的空格或者指定符号 print(str4.lstrip()) print(str5.rstrip()) str4= '***my name is xxx,my age is 18.' str5 = 'my name is xxx,my age is 18.***' print(str4.lstrip('*')) print(str5.rstrip('*')) # 2.lower(转换成小写),upper(转换成大写) str6 = 'mw name is Cc' print(str6.lower()) print(str6.upper()) # 3.startswith,endswith(判断字符串首位是否成立) print(str6.startswith("my")) print(str6.startswith("MY")) print(str6.endswith("Cc")) print(str6.endswith("cc")) # 4.format的四种玩法 # 方式一:按位置替换 str7 = 'my name is {},my age is {}' str7 = str7.format('cc',18) print(str7) # 方式二: 按照索引替换 str7 = 'my name is {0},my age is {1}' str7 = str7.format('cc',18,111) print(str7) # 方式三:指名道姓替换 str7 = 'my name is {name},my age is {age}' str7 = str7.format(age=18,name='cc') print(str7) # 6.join # 字符串拼接,会对列表中的数据按照某种标识进行拼接 name = 'cc' age = "18" print(':'.join([name,age])) # sex = 1 # print(':').join([name,age]) # 报错expected str instance,int found # print(':'.join([name,age,sex])) # 7. replace srt8 = 'old new' # 括号中第一个参数是旧参数,第二个是新参数 str8 = srt8.replace('old','python') print(str8) # 8.循环 list1 = {'cc',18,'male',3.0,9} for line in list1: print(line)