# Regular Expressions >> Using Python to Access Web Data

## Regular Expressions >> Using Python to Access Web Data

1. Which of the following best describes “Regular Expressions”?

- A way to calculate mathematical values paying attention to operator precedence
- The way Python handles and recovers from errors that would otherwise cause a traceback
**A small programming language unto itself**- A way to solve Algebra formulas for the unknown value

2. What will the ‘$’ regular expression match?

**The end of a line**- A new line at the end of a line
- The beginning of a line
- A dollar sign
- An empty line

3. What would the following mean in a regular expression? [a-z0-9]

- Match anything but a lowercase letter or digit
- Match an entire line as long as it is lowercase letters or digits
- Match any text that is surrounded by square braces
- Match any number of lowercase letters followed by any number of digits
**Match a lowercase letter or a digit**

4. What is the type of the return value of the re.findall() method?

- A single character
**A list of strings**- A boolean
- A string
- An integer

5. What is the “wild card” character in a regular expression (i.e., the character that matches any character)?

- *
- ?
- ^
- $
**.**✅- +

6. What is the difference between the “+” and “*” character in regular expressions?

**The “+” matches at least one character and the “*” matches zero or more characters**- The “+” matches upper case characters and the “*” matches lowercase characters
- The “+” matches the beginning of a line and the “*” matches the end of a line
- The “+” matches the actual plus character and the “*” matches any character
- The “+” indicates “start of extraction” and the “*” indicates the “end of extraction”

7. What does the “[0-9]+” match in a regular expression?

**One or more digits**- Zero or more digits
- Several digits followed by a plus sign
- Any number of digits at the beginning of a line
- Any mathematical expression

8. What does the following Python sequence print out?

x = 'From: Using the : character'

y = re.findall('^F.+:', x)

print(y)

- [‘From:’]
- :
- From:
- ^F.+:
**[‘From: Using the :’]**

9. What character do you add to the “+” or “*” to indicate that the match is to be done in a non-greedy manner?

- $
- g
**?**- ++
- **
- ^

10. Given the following line of text:

x = 'From: Using the : character'

y = re.findall('^F.+:', x)

print(y)

What would the regular expression ‘[email protected]+’ match?