Python简明教程

a = 123
print(a)
print(type(a))

123 
<class 'int'\>

b = [1, 2, 3]
print(b)
print(type(b))

[1, 2, 3] 
<class 'list'>

string = 'string'
print(string)
print(type(string))
bs = b'bytes'
print(bs)
print(type(bs))

string 
<class 'str'> 
b'bytes' 
<class 'bytes'>

    c = {'id': '123', 'name' : 'Leo'}
    print(c)
    print(type(c))

{'id': '123', 'name': 'Leo'} 
<class 'dict'>

d = (1, 'Leo', 99, 'boy')
print(d)
print(type(d))

(1, 'Leo', 99, 'boy') 
<class 'tuple'>

e = set('abcde')
print(e)
print(type(e))

{'c', 'd', 'e', 'b', 'a'} 
<class 'set'>

f = True
#f = None
print(f)
print(type(f))

True 
<class 'bool'>

a = 3
b = 5
if a > b :
    print (a)
elif a < b :
    print (b)
else :
    print("equal")

5

c = {'id': '123', 'name' : 'Leo'}
ch = 'name'

if ch in c :
    print(c[ch])
else :
    print("error")

Leo

for i in 'Python' :
    print(i, end = ' ')

P y t h o n 

i = 0
while i < 3 :
    print(i)
    i += 1
    if i == 2 :
        break;
else :
    #只有循环正常离开时才会执行，即没有break
    print(i)
print(i)

0 
1 
2

try :
    num = "10" ** 2
except :
    print("error")

error

#print([object, ...][, sep = ' '], [, end = '\n'],[, file = sys.stdout])
print('a', 'b', sep = '+', end = ' ')
print('= c')

a+b = c

"""
    python： 注释文档

"""
print(__doc__)

python： 注释文档

def fun(a, b) :
    return a + b

print(fun(2,3))

5

#lambda表达式
x = (lambda a = "Python", b = ",hello!": a + b )
print(x("lambda"))

lambda,hello!

class student(object) :

    def __init__(self, id, name) :
        self.id = id
        self.__name = name

    def print_student(self) :
        print(self.id, self.__name)

a = student('01111295', 'Leo')
a.print_student()
try :
    print('id:', a.id)
    print('name:', a.__name)
except :
    print('error')

01111295 Leo 
id: 01111295 
error

class fruit(object) :

    def __init__(self, name) :
        self.name = name

    def output_name(self) :
        print(self.name)


class apple(fruit) :

    def __init__(self, name) :
        self.name = name

a = apple("apple")
a.output_name()
type(a)

apple 
__main__.apple