Which Python Statements Are Incorrect?
Which statements below are INCORRECT? We can use a python list as the "key" in a python dictionary. Python tuples are immutable; therefore, we cannot perform my_tu = (1, 2) + (3, 4). String "3.14" multiplied by 2 generates "6.28". To obtain the first key:value pair in a dictionary named dict, we can use subscript dict[0].
No, Python lists cannot be used as keys in a Python dictionary. Dictionary keys must be immutable, meaning they cannot be changed after they are created. Since lists are mutable, they cannot be used as dictionary keys. However, tuples, which are immutable, can be used as dictionary keys. Yes, Python tuples are immutable, which means their values cannot be changed after they are created. However, we can perform operations on tuples, such as concatenation. The operation `my_tu = (1, 2) + (3, 4)` is valid and creates a new tuple `my_tu` with the values `(1, 2, 3, 4)`. The original tuples remain unchanged because tuples are immutable. Multiplying a string by an integer in Python repeats the string a specified number of times. In this case, the result of `"3.14" * 2` is "3.143.14". The string "3.14" is repeated twice because the multiplication operation duplicates the string, rather than performing a numerical multiplication. No, we cannot use subscript notation `dict[0]` to retrieve the first key-value pair in a Python dictionary. Dictionaries in Python are unordered collections, meaning the order of key-value pairs is not guaranteed. Therefore, there is no concept of a "first" pair in a dictionary. To access a specific key-value pair, you need to use the corresponding key as the subscript, such as `dict[key]`, which will return the associated value.