Python|仅使用列表中的键初始化字典

给定一个列表，任务是通过使用给定列表作为键来创建一个只有键的字典。

让我们看看我们可以完成这项任务的不同方法。

方法#1 ：通过迭代列表

# Python code to initialize a dictionary
# with only keys from a list
  
# List of keys
keyList = ["Paras", "Jain", "Cyware"]
  
# initialize dictionary
d = {}
  
# iterating through the elements of list
for i in keyList:
    d[i] = None
      
print(d)

输出：

{'Cyware': None, 'Paras': None, 'Jain': None}

方法#2：使用字典理解

# Python code to initialize a dictionary
# with only keys from a list
  
# List of Keys
keyList = ["Paras", "Jain", "Cyware"]
  
# Using Dictionary comprehension
myDict = {key: None for key in keyList}
print(myDict)

输出：

{'Paras': None, 'Jain': None, 'Cyware': None}

方法#3：使用 zip()函数

# Python code to initialize a dictionary
# with only keys from a list
  
# List of keys
listKeys = ["Paras", "Jain", "Cyware"]
  
# using zip() function to create a dictionary
# with keys and same length None value 
dct = dict(zip(listKeys, [None]*len(listKeys)))
  
# print dict
print(dct)

输出：

{'Cyware': None, 'Paras': None, 'Jain': None}

方法 #4：使用 fromkeys() 方法

# Python code to initialize a dictionary
# with only keys from a list
  
# List of keys
Student = ["Paras", "Jain", "Cyware"]
  
# using fromkeys() method
StudentDict = dict.fromkeys(Student, None)
  
# printing dictionary
print(StudentDict)

输出：

{'Cyware': None, 'Jain': None, 'Paras': None}