Python dict的常用方法示例代码

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }
new_dict = a.copy()
new_dict["ilpy1"]["company"] = "wtf"
print(new_dict)
print(a)
print(id(a))
print(id(new_dict))
print(id(new_dict["ilpy1"]["company"]))
print(id(a["ilpy1"]["company"]))

import copy

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }


new_dict = copy.deepcopy(a)
print(id(a))
print(id(new_dict))
a['ilpy1']['company'] = "666"
print(a)
print(new_dict)

import copy

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }
myList = ['aaa', 'bbb']
new_dict = dict.fromkeys(myList, "2")
print(new_dict)

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }
for key,value in a.items():
   print(key,value)

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }
# clear 清楚dict元素
# a.clear()
# print(a)

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }

a.update(a=1,b=2)
print(a)

a = {"ilpy1": {"company": "aaa"},
   "ilpy2": {"company": "bbb"}
   }

a.update([('1','2')])
print(a)
a.update((('1','2'),))
print(a)

# *********-list-*********
# 创建一个list
list1 = [1, 2, '力气,', 'afd']
print(type(list1))
print(list1)
# 添加单个元素
list1.append('ffff')
print(list1)
list2 = ['ff2', 34]
# 添加list
list2.extend(list1)
print(list2)
# 获取指定index的元素
print(list2[2])
# 删除指定values元素
list2.remove('value')
# 删除index=2的元素
del list2[2]
print(list2)
# 创建一个list1中的数据重复2次的list3
list3 = list1*2
print(list3)
# 排序
list4 = [1, 2, 8, 3, 12, 3]
# 升序
list4.sort()
print(list4)
# 降序
list4.reverse()
print(list4)
# 创建一个二维数组
list_muti = [[0, 0, 1]]*2
print(list_muti)
print(list_muti[0][1])

# *********-dict-*********
# 创建一个dict
dict1 = {}
print(type(dict1))
# 字典添加元素
dict1['a'] = 'value-a'
print(dict1)
# 批量添加元素
listx = []
for value in ('abced'):
  for key in (['abcde', 're', 1, 'n你re1', 3]):
    if key in listx:
      continue
    else:
      listx.append(key)
      # print(value)
      # print(key)
      dict1[key] = value
      break
print(dict1)
# dict里的fromkeys方法
dict1 = dict1.fromkeys(('a', 'ccc'), """ "nn'n'" """)
print(dict1)
# 获取keys之后转成list显示
keylist = list(dict1.keys())
print('%s' % keylist[0])
# 获取values之后转成list显示
valuelist = list(dict1.values())
print('%s' % valuelist[0])
print(dict1)
# 获取key对应的value
value = dict1['a']
print(value)
value2 = dict1.get('ccc', '木有找到')
# 与dict.get()方法一致，但是如果没有对应的key会自动创建一个key，value为none
dict1.setdefault('m')
print(dict1)
# 更新字典，如果没有对应的key会自动添加key-dict
dict1.update({'ccc': 'fff2'})
print(dict1)
value2 = dict1.get('ccc1', '木有找到')
print(value2)