python 自我检测题--part 2

1. Which of the following function capitalizes first letter of string?

capitalize()

2. 

• Iterate through dictionary keys: keys()
• Iterate through dictionary values: values()
• Iterate through dictionary key-value pairs: items()

3.  Which of the following function convert a single character to its integer value in python?

ord(x)

The ord() function returns the number representing the unicode code of a specified character.

4. - What is output for − min(''hello world'')

a blank space character

Explanation

python considers a blank space character as minimum value in a string

5. What is output of following code −

a = (1, 2)
a[0] +=1

 Type Error

Explanation

TypeError − ‘tuple' object does not support item assignment because a tuple is immutable.

6. Which of the following function checks in a string that all characters are titlecased?

Explanation

istitle() − Returns true if string has at least 1 character and all characters are titlecased.

• Use the Python string title() method to returns the titlecased version of a string.

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10. 

11. 

为什么 1.0 == 1 返回 True，1.0 is 1 返回 False，is 和 == 应该怎么理解和区别呢？

Python 中的对象包含三要素：id、type、value：

id 用来唯一标识一个对象，即在内存开辟了一块空间暂时存放这个变量

type 标识对象的类型，如之前所说的 int，float，bool，str等

value 就是对象的值

is 判断 a 对象是否是 b 对象，是通过 id 来判断的

== 判断的是 a 对象的值是否等于 b 对象的值，是通过 value 来判断的

注意：再次强调，Python 中，1 == 1.0 返回 True 是由于只比较他们的值，不考虑他们的精度，1 和 1.0 只是精度不同

12. What is the following function inserts an object at given index in a list?

list.insert(index, obj)

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