python--數據類型

#python2

a = 13
a
13

type(a)
<type ‘int’>

a = 1234124512512341235124512512
type(a)
<type ‘long’>

#python3

a = 13
type(a)
<class ‘int’>

a = 1245123512512561251245124124124

type(a)
<class ‘int’>

a = ‘hello’
a
‘hello’

a.center(40)
’ hello ’

a.center(40,’’)
'hello’

print(“學生管理系統”.center(50,’-’))
----------------------學生管理系統----------------------

print(“學生管理系統”.center(50,’*’))
學生管理系統

a = 1
float(a)
1.0

b = 2.3
int(b)
2

float(b)
2.3

str(b)
‘2.3’

str = ‘westos’
float(str)
Traceback (most recent call last):
File “”, line 1, in
ValueError: could not convert string to float: ‘westos’

#刪除內存中的變量

a = 1.2
a
1.2

del a
a
Traceback (most recent call last):
File “”, line 1, in
NameError: name ‘a’ is not defined

#布爾數據類型

a = ‘hello’
bool(a)
True

bool(0)
False

b = ‘’
b
‘’

bool(b)
False