python—打印字典 ，collection模块中Orderedict用法，字典与文件

一. python 中，如果字典里面又有字典，则输出不好看。

方法一：使用内置的pprint
方法二：自己写一个函数

method 1:

Python代码

>>> d = {1:{'who':{'name':'Michael','age':20,'job':{'P':'90-91','G':'91-93'}}},2:{'who':{'name':'Mary','age':18,'job':{'P':'90-93','G':'93-95'}}}}  
>>> d  
{1: {'who': {'job': {'P': '90-91', 'G': '91-93'}, 'age': 20, 'name': 'Michael'}}, 2: {'who': {'job': {'P': '90-93', 'G': '93-95'}, 'age': 18, 'name': 'Mary'}}}  
>>> import pprint  
>>> pprint.pprint(d)  
{1: {'who': {'age': 20,  
             'job': {'G': '91-93', 'P': '90-91'},  
             'name': 'Michael'}},  
 2: {'who': {'age': 18, 'job': {'G': '93-95', 'P': '90-93'}, 'name': 'Mary'}}} 

　

method 2:
Python代码

>>> d = {1:{'who':{'name':'Michael','age':20,'job':{'P':'90-91','G':'91-93'}}},2:{'who':{'name':'Mary','age':18,'job':{'P':'90-93','G':'93-95'}}}}  
>>> d  
{1: {'who': {'job': {'P': '90-91', 'G': '91-93'}, 'age': 20, 'name': 'Michael'}}, 2: {'who': {'job': {'P': '90-93', 'G': '93-95'}, 'age': 18, 'name': 'Mary'}}}  
  
>>> def print_dict (d,n=0):  
    for k,v in d.items():  
        print '	'*n,  
        if type(v)==type({}):  
        print "%s : {" % k  
            print_dict(v,n+1)  
        else:  
            print("%s : %s" % (k,v))  
    if n!=0:  
        print '	'*(n-1)+ '}'  
  
          
>>> print_dict(d)  
 1 : {  
    who : {  
        job : {  
            P : 90-91  
            G : 91-93  
        }  
        age : 20  
        name : Michael  
    }  
}  
 2 : {  
    who : {  
        job : {  
            P : 90-93  
            G : 93-95  
        }  
        age : 18  
        name : Mary  
    }  
}  

　　

二.Orderedict

orderdDict是对字典类型的补充，他记住了字典元素添加的顺序

注意：字典默认循环只输出key

复制代码
import collections
dic = collections.OrderedDict()
dic["k1"] = "v1"
dic["k2"] = "v2"
dic["k3"] = "v3"
print(dic)
#实现原理：相当于用列表（有序）来维护字典（无序）排序,以下仅供理解
# dic = {"k1":"v1","k2":"v2"}
# li = ["k1","k2"]
# for i in li:
#     print(dic.get(i))

执行结果：无论执行多少次结果一样
OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')])

　　

def popitem(self, last=True):

　

#有序删除和指定删除
import collections
dic = collections.OrderedDict()
dic["k1"] = "v1"
dic["k2"] = "v2"
dic["k3"] = "v3"
print(dic)
dic.popitem()    #有序拿掉，每次拿掉最后一个，相当于内存的栈存放，后进先出原则，而pop()就是强制拿出指定的值
print(dic)
 
 执行结果：
OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')])
OrderedDict([('k1', 'v1'), ('k2', 'v2')])

　　

def move_to_end(self, key, last=True):

　　

#把指定键值移到最后
import collections
dic = collections.OrderedDict()
dic["k1"] = "v1"
dic["k2"] = "v2"
dic["k3"] = "v3"
print(dic)
dic.move_to_end("k1")    #把指定键值移到最后
print(dic)
 
#执行结果：
OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')])
OrderedDict([('k2', 'v2'), ('k3', 'v3'), ('k1', 'v1')])

　　

def setdefault(self, key, default=None):

　

#添加默认键
import collections
dic = collections.OrderedDict()
dic["k1"] = "v1"
dic["k2"] = "v2"
dic["k3"] = "v3"
print(dic)
dic.setdefault("k4","v4")    #默认键值为None,不过可以添加值
print(dic)
 
#执行结果：
OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')])
OrderedDict([('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3'), ('k4', 'v4')])

　　

#举一个实例：
from collections import OrderedDict
items = (
    ('A', 1),
    ('B', 2),
    ('C', 3)
)
regular_dict = dict(items)
ordered_dict = OrderedDict(items)
print 'Regular Dict:'
for k, v in regular_dict.items():
    print k, v
print 'Ordered Dict:'
for k, v in ordered_dict.items():
    print k, v
# Result:
Regular Dict:
A 1
C 3
B 2
Ordered Dict:
A 1
B 2
C 3

三.python读文件保存到字典，修改字典并写入新文件

tcode={}  
transcode={}  
def GetTcode():  
#从文本中获取英文对应的故障码，并保存在tcode字典(故障码文本样例：oxff,0xff,0x00,0x01,    "Fuel Volume Regulator Control Circuit High")  
    with open('text_en.txt','r+')as fileone:  
        for line in fileone.readlines():  
            if not line:  
                continue  
            line=line.strip()  
            titems=line.split('	')  
            strkey=titems[0].lower()  
            strtemp=titems[1]  
            tcode[strkey]=strtemp  
  
def GetTransCode():  
#从文本中获取中文对应的故障码，并保存在tcode字典(故障码文本样例：oxff,0xff,0x00,0x01,    "燃油调节器控制电路过高")  
    with open('text_cn.txt','r+') as fileone:  
        for line in fileone.readlines():  
            if not line:  
                continue  
            line=line.strip()  
            transcode[line.split('	')[0].lower()]=line.split('	')[1]  
  
def ReplaTransCode():  
#将已经翻译的中文故障码在英文文本中用ID查找出来并替换，对新的tcode字典key进行排序，并写入新的文本中  
    for findkey in transcode.keys():  
        if tcode.get(findkey,-1)!= -1:  
            tcode[findkey]=transcode[findkey]  
    templine=[]  
    lkeys=tcode.keys()  
    lkeys.sort()  
    for key in lkeys:  
        value=tcode.get(key)  
        key=key.upper().replace("0X","0x")  
        templine.append("%s	%s
"%(key,value))  
    with open('text_trans.txt','w+') as filetwo:  
        filetwo.writelines(templine)  
  
  
if __name__ == '__main__':  
    GetTcode()  
    GetTransCode()  
    ReplaTransCode()