python物件持久化

pickle模組

import pickle

person =
s = pickle.dumps(person)
p = pickle.loads(s)
pickle.dump(person,
open
('pickle_db'
,'wb'))
p = pickle.load(
open
('pickle_db'
,'rb'))
print
(p)print
(type
(p))

import shelve

scores =[99
,100,88
]student =
db = shelve.
open
('shelve_student'
)#宣告建立乙個資料庫
db['s'
]= student #將字典表student序列化到資料庫檔案裡，並且賦予鍵值's'
db['scores'
]= scores
len(db)
#檢查資料庫中有幾個物件，用len()檢視鍵值
2temp_student = db[
's']
temp
traceback (most recent call last)
: file ""
, line 1,in
nameerror: name 'temp'
isnot defined
temp_student
type
(temp_student)
<
class
'dict'
>
temp_scores[99
,100,88
]type
(temp_scores)
<
class
'list'
>

import  shelve

class
student
:def
__init__
(self,name,age)
: self.name = name
self.age = age
def__str__
(self)
:return self.name
defwirte_shelve()
: s = student(
'tom',25
) db = shelve.
open
('shelve_student_db'
) db[
's']
= s db.close(
)def
read_shelve()
: db = shelve.
open
('shelve_student_db'
) st = db[
's']
print
(st)
print
(st.name)
print
(st.age)
db.close(
)if __name__ ==
'__main__'
: read_shelve(
)

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