python基础知识--2字符串

1.字符串操作

1.字符串连接

print('A'+'B')

运行结果:AB

2.字符串多次连接

print('Python ' * 3)

运行结果:Python Python Python 

3.字符串切片操作

print('Python'[0])

运行结果:P

4.strip()


# 去除空白字符

print(' abc123abc '.strip())
运行结果:abc123abc

# 去除指定字符
print('123abc123'.strip('21'))
运行结果:3abc123


print('123abc321'.strip('213'))
运行结果:abc

print('4123abc123'.strip('21'))
运行结果:'4123abc123'

#lstrip用于去除最左边的字符
print(' abc123 '.lstrip())
运行结果:abc123

rstrip用于去除最右边的字符
print(
' abc123 '.rstrip())
运行结果:abc123


判断字符串开头结尾字符
print('apple'.startswith('a'))
运行结果:True


返回字符位置

print('apple'.find('m'))

运行结果:-1

字符串替换

print('lemon'.replace('lemon','apple'))

运行结果:apple

字符串其他操作

print(len('apple'))

运行结果:5

print('lemonmmm'.count('m'))

运行结果:4

Print('apple'.upper())
运行结果:APPLE

print('APPLE'.lower())
运行结果:apple

print('apple'.center(10,'-'))
运行结果:--apple---


print('apple'.center(4,'-'))
运行结果:apple


print('applepear'.isalpha())
运行结果:True

print('123456'.isdigit())
运行结果:True

print('abc123'.isalnum())
运行结果:True
 

% 格式化字符串

print('hello %s,%s' %('lemon','python'))
运行结果:hello lemon,python

print('i am %d years old' % (16))
运行结果:
i am 16 years old

print(
'%.5f' % (3.14))
运行结果:
3.14000

print('i am %(name)s, i am %(age)s years old' %{'name':'lemon','age':16})
运行结果:i am lemon, i am 16 years old

format格式化字符串


print('hello {}'.format('world'))

运行结果:hello world


print('hello {1} {0}'.format('lemon','python'))
运行结果:hello python lemon

print('i am {name}, i am {age} years old'.format(name = "python",age = 16))
运行结果:i am python, i am 16 years old
 
Number(数字):整型,浮点型与复数及布尔类型

整型


# bin 是向二进制转化 0b1010 # oct 是向八进制转化 0o12 # int 是向十进制转化 10 # hex 是向十六进制转化 0xa


浮点型

复数










原文地址:https://www.cnblogs.com/tester007/p/13778241.html