(i) Differentiate between 'w' and 'a' file modes in Python.
(ii) Consider a binary file, items.dat, containing records stored in the given format:
text
{item_id: [item_name, amount]}
Write a function, Copy_new(), that copies all records whose amount is greater than 1000 from items.dat to new_items.dat.

Question

(i) Differentiate between 'w' and 'a' file modes in Python.

(ii) Consider a binary file, items.dat, containing records stored in the given format:

text

{item_id: [item_name, amount]}

Write a function, Copy_new(), that copies all records whose amount is greater than 1000 from items.dat to new_items.dat.

Accepted Answer

(i)
**'w' mode** opens a file for writing. If the file does not exist, a new file is created. If it exists, its contents are truncated and replaced. The file pointer is positioned at the beginning.

**'a' mode** opens a file for appending. If the file does not exist, a new file is created. If it exists, the contents are preserved and the file pointer is placed at the end so new data is added after existing data.

(ii)
```python
import pickle

def Copy_new():
    try:
        F1 = open("items.dat", "rb")
        F2 = open("new_items.dat", "wb")
        try:
            while True:
                D1 = pickle.load(F1)
                for K, V in D1.items():
                    if V[1] > 1000:
                        pickle.dump({K: V}, F2)
        except EOFError:
            pass
        F1.close()
        F2.close()
    except:
        print("File Opening Error")
```

Question 34

Answer

Explanation