python自学第3天（MJ培根）

python数据类型

 

# 字符串索引与切片
# 索引
#索引下标从0开始
#取出任意元素
# s = 'ABCDLSESRF'
# s1 = s[0]
# s2 = s[2]
# s3 = s[-1]
# s4 = s[0:3]    #切片取,遵循顾头不顾腚;
# s5 = s[-2]     #切片反向取
# s6 = s[0:-1]
# s7 = s[:]      #取整个字符串
# s8 = s[-1::-1] #反向取整个字符串,步长为负，可以反向取
# s9 = s[0:5:2]  #步长取
# print(s9)
#
# # 小贴士
# ### 取出前n位字符，即[0:n+1],表示多一位，再根据顾头不顾腚，得到结果
# cat = 'GaleraClusterforMySQLisatrue'
# cat1 = cat[0:5]
# cat2 = cat[6:13]  # 取出中间切片n位长度，n=尾-头
# cat3 = cat[16:21]
# print(cat3)

# 字符串常用操作
# str_s = 'acEQ'
# you_input = input("请输入验证码，不区分大小写：")
#
# if you_input.upper() == str_s.upper():
#     print("congratulation，you win")
# else :
#     print("sorry")

# s = 'huawei iphone xiaomi vivo'
# a = "======hello world======"
# b = "   hello world================"
# c = "huaWei"
# d = "huaweixiaomivivoiphone"
# s1 = s.upper()
# s2 = s.lower()
# s3 = s.capitalize()                  # 首字母大写
# s4 = s.title()                       # 首单词大写
# s5 = a.strip()                       # 默认删除前后空白（空格、换行符），Return a copy of the string with leading and trailing whitespace removed.If chars is given and not None, remove characters in chars instead.
# s6 = a.rstrip("=")                   # 删除右边=号
# s7 = b.lstrip()                      # 删除左边空格
# s8 = c.swapcase()                    # 大小写翻转
# s9 = len(c)                          # 长度
# s10 = d.startswith("hua")            # 以什么字符开头，可以单个，也可以整体
# s11 = d.startswith("hua",0,9)        # 以什么字符开头, 支持切片
# s12 = d.endswith("iphone",1)
#
# s13 = s.find("iphone")               # 寻找元素的对应的索引下标
# s14 = s.find("xiaomi",0,20)          # 寻找元素的对应的索引下标，支持切片
# s15 = s.find("level")                # find查找不到的元素返回-1
#
# s16 = s.index("iphone")              # index类似find功能，但找不到会报错
# s17 = s.count("i")                   # 元素出现了多少次
#
# s18 = s.split()                      # split默认将字符串以空格切分
#
# # print("\thuawei")                  # 使用制表符来添加空白
# # print("\nhuawei\niphone")          # 添加换行
# print(s18)

# format格式化输出
#s = '我叫{}，今年{}，爱好{}，再说一下我叫{}'.format('peigen','66','girl','peigen')
# s = '我叫{0}，今年{1}，爱好{2}，再说一下我叫{0}'.format('peigen','66','girl')
# s = '我叫{name}，今年{age}，爱好{hobby}，再说一下我叫{name}'.format(name='peigen',age='66',hobby='girl')
# print(s)

#is系列
# name1 = "afejafejal12354325alfeao"
# name2 = "jkhgjg我是中国人9700"
# name3 = "123123123323423042347508"
# print(name1.isalnum())               # 字符串由字母或数字组成
# print(name2.isalpha())               # 字符串由字母组成
# print(name3.isdigit())               # 字符串由数字组成