python2

1.
name = "郑建文"
# if "郑"in name:
# print('OK')
# else:
# print('Error')
# if '文'not in name:
# print('1')
# else:
# print('2')
# 判断某个东西是否在某个东西里面包含
# in not in
# 2.
# 布尔值：真，假
# 大小对比、not in 与 in、not、（结果都是布尔值）
# 3.
# 补充：（逻辑运算规则）
# 先计算括号内
# 执行顺序：从前到后，结果：
# True OR ==> True
# True AND ==> 继续走
# False AND ==> False
# 4.
# 赋值运算符
# count = count + 1
# count += 1
# count -= 1
# count //= 1
# count %= 1
# count /= 1
# 5.
# num = 123
# v = num.bit_length()
# print(v)
# name1 = "shizhengwen"
# v1 = name1.upper()
# print(v1)
# 5.
# int (按住ctrl)显示int下面所有的用法
# s1 = "alex"
# s2 = "root"
# s1.upper()
# s1.title()
# s1.startswith('xx')
# 6.
# str(五六个重要的)
# list(五六个重要的)
# tuple（几乎没有）
# dict（四五个重要的）
# bool
# 7.
# int(将字符串转换为数字)
# a = "123"
# b = int(a)
# b = b + 1000
# 8.
# type的用法
# a = "123"
# print(type(a),a)
# b = int(a)
# print(type(b),b)
# 9.
# num = "0011"
# int（num,base=2）
# #以二进制方式进行转换成十进制
# print（v）
# num = "b"
# v = int(num,base=16)
# print(v)#(以十六进制的方式转换成十进制)
# 10.
# age = 3
#1 1
#2 10
#3 11
#4 100
#5 101
#当前数字的二进制，至少用n位表示
# r = age.bit_length()
# print(r)
# 11.(首字母大写)
# test = "alex"
# v = test.capitalize()
# print(v)
# 12.(把大些变成小些)（更牛逼，范围更广）
# test = "aLex"
# v1 = test.casefold()
# print(v1)
# 13.(把大写变为小些)
# test = "aLex"
# v2 = test.lower()
# print(v2)
# 14.
# test = "alex"
# v = test.center(20)
# print(v)
# alex (输出，一共20个位置)
# test = "alex"
# v = test.center(20,'*')
# print(v)
# test = "alexalexalexalex"
# v = test.count('ex')
# print(v)
#def count(self, sub, start=None, end=None):
# test = "alexalexalexalex"
# v = test.count('ex',5,9)
# print(v)
# 15.(以什么为结尾)
#def endswith(self, suffix, start=None, end=None):
# test = "alex"
# v = test.endswith("x")
# print(v)
# 16.（以什么为开头）
# test.startswith()
# 17.(寻找子序列)
# test = "alexalexalex"
# test.find('ex')#从开始往后找，找到第一个获取其位置
# print(v)
# #def find(self, sub, start=None, end=None):（起始和结尾一般是大于等于前面那个，小于后面那个）
# 18.
#def format(self, *args, **kwargs):（传值）(格式化，将一个字符串中的占位符替换为指定的值)
test = 'i am {name},age {a}'
print(test)
v = test.format(name='alex',a=19)
print(v)
19.#另一种不同书写方式的格式化,传入的值({"name":'alex',"a":19})
#def format_map(self, mapping):
test = 'i am {name},age {a}'
v2 = test.format_map({"name":'alex',"a":19})
20.（索引，未找到错误）（find未找到返回-1）
#def index(self, sub, start=None, end=None):
21.（判断字符串中是否只包含字母和数字）
test = "uasf"
v = test.isalnum()
print(v)