Write a code segment that prompts the user for a filename. If the file exists, the program should print its contents on the terminal. Otherwise, it should print an error message.

Jack is developing a program that calls for converting a list of words to uppercase. He tries out a strategy for this task in the Python shell, as follows:

$>>>$ listOfWords $=["$Apple$",$ "orange", "banana"$]$

$>>>$ for word in listOfWords:

word $=$ word.upper$()$

$>>>$ listOfWords

$[\text{'}$Apple$\text{'},$ 'orange', 'banana'$]$

Jack$$s strategy does not appear to produce the expected result. Describe the error, explain why it happened, and suggest a correction.

Assume that the variable data refers to the dictionary $\{\text{'}$b$\text{'}$:$20,\text{'}$a$\text{'}$:$35\}.$ Write the expressions that perform the following tasks:

Replace the value at the key $\text{'}$b$\text{'}$ in data with that value$$s negation.

Add the key$/$value pair $\text{'}$c$\text{'}$:$40$ to data.

Remove the value at key $\text{'}$b$\text{'}$ in data, safely.

Print the keys in data in alphabetical order.