Which of the following is the correct way to create a list in Python?
- list = "1, 2, 3, 4"
- list = (1, 2, 3, 4)
- list = [1, 2, 3, 4]
- list = {1, 2, 3, 4}
The correct way to create a list in Python is by using square brackets, as shown in "list = [1, 2, 3, 4]". Square brackets denote a list in Python.
Which of the following is not a Python standard library?
- math
- numpy
- os
- stdlib
numpy is not a Python standard library; it's a third-party library commonly used for numerical and scientific computing. Python's standard libraries include os and math.
What is the primary use of the pass statement in Python?
- To act as a placeholder
- To indicate a successful run
- To skip a loop iteration
- To terminate the program
The primary use of the 'pass' statement in Python is to act as a placeholder. It does nothing when executed and is often used as a temporary placeholder for code that will be implemented later.
Which dictionary method provides a view on dictionary's items in the form of tuples?
- dict.items()
- dict.tuples()
- dict.values()
- dict.viewitems()
The dict.items() method returns a view object that displays a list of a dictionary's (key, value) tuple pairs, making it useful for iterating through a dictionary's items.
A colleague is seeing unexpected behavior in a function. The function uses a list as a default argument and modifies it. Every time the function is called without this argument, the list seems to retain its changes. What's the likely cause?
- Caching of previous function calls
- Incorrect usage of global variables
- Python's behavior with mutable default arguments
- The list is defined as a class attribute
The likely cause is Python's behavior with mutable default arguments. The list retains its changes because it's a mutable object shared among calls.
If my_list = [10, 20, 30, 40], what does the expression my_list[-2::-2] evaluate to?
- [20, 10]
- [30, 10]
- [40, 20]
- [40, 30]
The expression my_list[-2::-2] starts at the second-to-last element of the list (which is 30), and it then steps backward by 2 positions, so it selects every second element in reverse order. Therefore, the result is [20, 10].
The pass statement in Python is essentially a _______ operation, meaning it doesn't perform any action.
- Break
- Continue
- Halt
- No-op
The 'pass' statement is a no-op or a no-operation statement. It is used as a placeholder when syntactically required but no action is desired. It doesn't perform any operation.
Which memory management technique does Python primarily utilize?
- Garbage Collection (GC)
- Manual Memory Management (malloc/free)
- Reference Counting
- Stack Allocation
Python primarily utilizes Garbage Collection (GC) for memory management. It automatically deallocates memory occupied by objects that are no longer in use, making memory management more convenient and reducing the risk of memory leaks.
Which Python module provides functionality to read and write data in CSV format?
- csv
- dataio
- table
- textfile
The csv module in Python provides functionality for reading and writing data in CSV (Comma-Separated Values) format, making it a popular choice for working with spreadsheet-like data.
The file method _______ is used to obtain the current position of the file read/write pointer.
- current_position()
- file_position()
- get_position()
- tell()
The tell() method in Python's file handling is used to obtain the current position of the file read/write pointer. It returns an integer representing the current position in bytes. This is crucial when you want to navigate through a file or keep track of where you are when reading or writing data.