python 字典

dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};

print "dict['Name']: ", dict['Name'];
print "dict['Age']: ", dict['Age'];
print "dict['School']", dict['School']

dict['Name']:  soyoungboy
dict['Age']:  27
dict['School'] Xian University of Finance and Economics

#!/usr/bin/python

dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};

dict['Age'] = 8;  # 修改字段
dict['Class'] = "First";  # 新增字段

print "dict['Age']: ", dict['Age'];
print "dict['Class']: ", dict['Class'];
print dict

dict['Age']:  8
dict['Class']:  First
{'School': 'Xian University of Finance and Economics', 'Age': 8, 'Name': 'soyoungboy', 'Class': 'First'}

#!/usr/bin/python
# coding=utf-8

dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};

dict['Age'] = 8;  # 修改字段
dict['Class'] = "First";  # 新增字段

print dict
del dict['Age']  # 删除age字段
print "删除Age后的dict = ", dict
dict.clear();  # 清空dict
print dict;

{'School': 'Xian University of Finance and Economics', 'Age': 8, 'Name': 'soyoungboy', 'Class': 'First'}
删除Age后的dict =  {'School': 'Xian University of Finance and Economics', 'Name': 'soyoungboy', 'Class': 'First'}
{}

#!/usr/bin/python
# coding=utf-8

dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};
dict1 = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};
dict2 = {'Name': 'boy', 'Age': 25, 'School': 'Xian University of Finance and Economics'};
# 如果两个字典的元素相同返回0，如果字典dict1大于字典dict2返回1，如果字典dict1小于字典dict2返回-1
print cmp(dict, dict1);
print cmp(dict1, dict2);
print cmp(dict2, dict1);
# 计算字典元素个数，即键的总数。
print len(dict);
print str(dict);
# 返回输入的变量类型，如果变量是字典就返回字典类型。
print type(dict['Name'])
print type(dict['Age'])

0
1
-1
3
{'School': 'Xian University of Finance and Economics', 'Age': 27, 'Name': 'soyoungboy'}
<type 'str'>
<type 'int'>

#!/usr/bin/python
# coding=utf-8

dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};
print dict.copy();  # 返回一个字典的浅复制
fromkeys = dict.fromkeys(dict)  # 创建一个新字典，以序列 seq 中元素做字典的键，val 为字典所有键对应的初始值
print fromkeys;
dict_fromkeys = dict.fromkeys(dict, 'I Love John')  # 创建一个新字典，以序列 seq 中元素做字典的键，val 为字典所有键对应的初始值
print dict_fromkeys;
dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};
print dict.get('Name', 'defaultValue');  # 返回指定键的值，如果值不在字典中返回default值,其实就是根据键获取值
print dict.get('name', 'defaultValue');
print dict.items();  # 以列表返回可遍历的(键, 值) 元组数组
print dict.keys();  # 以列表返回一个字典所有的键
dict.setdefault('Height', 'defaultValue');  # 和get()类似, 但如果键不存在于字典中，将会添加键并将值设为default
print dict;
dict = {'Name': 'soyoungboy', 'Age': 27, 'School': 'Xian University of Finance and Economics'};
dict2 = {'Name': 'john', 'Age': 27, 'School': 'South China Agricultural University'};
dict.update(dict2);  # 把字典dict2的键/值对更新到dict里
print dict;
print dict.values();  # 以列表返回字典中的所有值

{'School': 'Xian University of Finance and Economics', 'Age': 27, 'Name': 'soyoungboy'}
{'School': None, 'Age': None, 'Name': None}
{'School': 'I Love John', 'Age': 'I Love John', 'Name': 'I Love John'}
soyoungboy
defaultValue
[('School', 'Xian University of Finance and Economics'), ('Age', 27), ('Name', 'soyoungboy')]
['School', 'Age', 'Name']
{'School': 'Xian University of Finance and Economics', 'Age': 27, 'Name': 'soyoungboy', 'Height': 'defaultValue'}
{'School': 'South China Agricultural University', 'Name': 'john', 'Age': 27}
['South China Agricultural University', 'john', 27]