my_keys = calendar.keys()first, *rest = my_keysprint(first) The output will be: January as expected. Thus, we have learnt three different ways to obtain the first key in a Python dictionary. Which one is your favorite? Also seehow to sort a Python dictionary by keys ...
print(student) ... Alice Bob Charlie Diana Ethan Fiona George Hannah In these examples, you first iterate over the keys of a dictionary using the dictionary directly in the loop header. In the second loop, you use the .keys() method to iterate over the keys. Both loops are equivalent....
#!/usr/bin/python tinydict = {'Name': 'Runoob', 'Age': 7, 'Class': 'First'} print "tinydict['Alice']: ", tinydict['Alice']以上实例输出结果:tinydict['Alice']: Traceback (most recent call last): File "test.py", line 5, in <module> print "tinydict['Alice']: ", tinydict...
# 与列表一样,del 函数可以用来删除字典中特定的键值对,例如: del d['two'] print(d) {} update()方法更新字典 可以通过索引来插入、修改单个键值对,但是如果想对多个键值对进行操作,这种方法就显得比较麻烦,好在有 update 方法: dict.update(newd) In [39]: person = {'first':'jm', 'last':'to...
#!/usr/bin/python dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'} dict['Age'] = 8 # 更新 dict['School'] = "RUNOOB" # 添加 print "dict['Age']: ", dict['Age'] print "dict['School']: ", dict['School']以上...
#!/usr/bin/python dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'} dict['Age'] = 8 # 更新 dict['School'] = "RUNOOB" # 添加 print "dict['Age']: ", dict['Age'] print "dict['School']: ", dict['School']以上...
my_dict = {'person1': {'name': 'John', 'age': 25}, 'person2': {'name': 'Alice', 'age': 30}} def print_nested_dict(dictionary): for key, value in dictionary.items(): if isinstance(value, dict): print_nested_dict(value) else: print(key, value) print_nested_dict(my_dict...
Python 複製 planet['orbital period'] = 4333 # planet dictionary now contains: { # name: 'jupiter' # moons: 79 # orbital period: 4333 # } 重要 索引鍵名稱 (就像 Python 中的其他所有項目),會區分大小寫。 因此,'name' 和'Name' 會在Python 字典中視為兩個不同的索引鍵。
dict= {'Name':'Zara','Age': 7,'Class':'First'};print"dict['Alice']:", dict['Alice']; 以上实例输出结果: #KeyError: 'Alice'[/code] 三、修改字典 向字典添加新内容的方法是增加新的键/值对,修改或删除已有键/值对如下实例: dict= {'Name':'Zara','Age': 7,'Class':'First'}; ...
print "dict['Alice']: ", dict['Alice'] KeyError: 'Alice' 修改字典 向字典添加新内容的方法是增加新的键/值对,修改或删除已有键/值对如下实例: 实例 #!/usr/bin/python dict = {'Name': 'Zara', 'Age': 7, 'Class': 'First'} dict['Age'] = 8 # 更新 dict['School'] = "RUNOOB" #...