python 基础知识

第一个python程序 hello world

"""
hello world
"""
name = input("What is your name: ")
print("Hello %s" % name)
import time
time.sleep(2)

What is your name: zenos
Hello zenos

字符串

"""
测试字符串
"""

# 1.转义成字符串
print('{:=^50}'.format('1'))
print('let\'s go')

# 2.特殊的字符串拼接方式
print('{:=^50}'.format('2'))
print("hello" 'world')

x = "hellp"
y = 'world'
# print(x y)

# 3.字符串拼接
print('{:=^50}'.format('3'))
print(x+y)

# 4.str repr
print('{:=^50}'.format('4'))
print(str("Hello,\n world"))
# 类似直接交互式解释器输出
print(repr("Hello,\n world"))


# 5.长字符串
print('{:=^50}'.format('5'))
string = """
    Hello,
    world
"""
print(string)

# 6.反斜杠会被解释器忽略
print('{:=^50}'.format('6'))
print("Hello,\
world")

# 7.原始字符串
print('{:=^50}'.format('7'))
# string1 = 'C:\Users\87600\Desktop\python_study\MyPro01'
# print(string1)
string = r'C:\Users\87600\Desktop\python_study\MyPro01'
print(string)

# 8.最后一个字符为\
print('{:=^50}'.format('8'))
string = r'C:\Users\87600\Desktop\python_study\MyPro01' '\\'
print(string)

# 9.Unicode字符
print('{:=^50}'.format('9'))
string = '\u4e00'+'\u9FA5'
print(string)
string = '\N{CAT}'
print(string)

# 10.字节编码
print('{:=^50}'.format('10'))
# 为了更好的使用与类似C的语言进行互操作，将字符串转换为字节序列
# python中字符串默认为unicode编码

# 将字符串以ASCII规则进行编码成bytes即  unocode -> ASCII bytes
print("Hello, world".encode("ASCII"))
print("Hello, world".encode("UTF-8"))
print("Hello, world".encode("UTF-32"))

# 特殊字符不能以ASCII进行编码
print("H哈llow, world".encode("ASCII", 'ignore'))
print("H哈llow, world".encode("ASCII", 'replace'))
print("H哈llow, world".encode("ASCII", 'xmlcharrefreplace'))

# 但是可以使用utf-8编码
print("H哈llow, world".encode('utf-8'))

# 使用decode进行解码
print("H哈llow, world".encode('utf-8').decode())

# 11.bytes str对象
print('{:=^50}'.format('11'))
bytes_obj = bytes('Hello world', encoding='utf-8')
str_obj = str(b'Hello world', encoding='utf-8')
print('bytes_obj: ',bytes_obj)
print('str_obj: ',str_obj)

# 12.bytearray
print('{:=^50}'.format('12'))
x = bytearray(b'Hello')
x[1] = ord(b'u')

print(x)

========================1.========================
2
========================2.========================
2
======================2.2.1=======================
Gumby
24
======================2.2.2=======================
2
Gumby
{'name': 'Gumby', 'age': 24, 'gender': True}
{'name': 'Gumby', 'age': 24}
True
False
{'name': 'Gumby', 'age': 24, 3.1: '实数', '3.1': '字符串', (3, 1): '元组'}
======================2.2.3=======================
alice's phonenumber is 111
{}
{'name': 'alice', 'students': ['zenos', 'herry']}
{'name': 'zenos', 'students': ['zenos', 'herry']}
{'name': 'alice', 'students': ['zenos', 'herry']}
{'name': 'zenos', 'students': ['herry']}
{'name': 'alice', 'students': ['herry']}
{'name': 'alice', 'students': ['zenos', 'herry']}
{'name': 'zenos', 'students': ['zenos', 'herry']}
{'name': 'alice', 'students': ['zenos', 'herry']}
{'name': 'zenos', 'students': ['herry']}
{'name': 'alice', 'students': ['zenos', 'herry']}
{'name': 'zenos', 'age': 'zenos'}
N/A
dict_items([('name', 'zenos'), ('age', 'zenos')])
PS C:\Users\87600\Desktop\python_basic_learning> python -u "c:\Users\87600\Desktop\python_basic_learning\1.basic_knowledge\1.hello_world.py"
What is your name: zenos
Hello zenos
PS C:\Users\87600\Desktop\python_basic_learning> a^C
PS C:\Users\87600\Desktop\python_basic_learning> python -u "c:\Users\87600\Desktop\python_basic_learning\1.basic_knowledge\2.test_str.py"
========================1=========================
let's go
========================2=========================
helloworld
========================3=========================
hellpworld
========================4=========================
Hello,
 world
'Hello,\n world'
========================5=========================

    Hello,
    world

========================6=========================
Hello,world
========================7=========================
C:\Users\87600\Desktop\python_study\MyPro01
========================8=========================
C:\Users\87600\Desktop\python_study\MyPro01\
========================9=========================
一龥
🐈
========================10========================
b'Hello, world'
b'Hello, world'
b'\xff\xfe\x00\x00H\x00\x00\x00e\x00\x00\x00l\x00\x00\x00l\x00\x00\x00o\x00\x00\x00,\x00\x00\x00 \x00\x00\x00w\x00\x00\x00o\x00\x00\x00r\x00\x00\x00l\x00\x00\x00d\x00\x00\x00'
b'Hllow, world'
b'H?llow, world'
b'H哈llow, world'
b'H\xe5\x93\x88llow, world'
H哈llow, world
========================11========================
bytes_obj:  b'Hello world'
str_obj:  Hello world
========================12========================
bytearray(b'Hullo')