Homework 3

Regular Expression Puzzles

1. Find: \s{2,} Replace: ,

• Find 2 or more spaces in a row

• Replace with a comma

2. Find: (\w+), (\w+), (.*) Replace: \2 \1 (\3)

• find word 1, word 2, all the rest of the line
• replace with word 2 word 1 and the rest of the line in ()

3. Find: (.mp3)(\s) Replace: .mp3 \n

• Find each place where .mp3 is followed by a single space
• replace the single space with a line break

4. Find: (\d{4}) (.*)(.mp3) Replace: \2_\1.mp3

• Find 4 digit number followed by all the rest until .mp3

• Replace starting the line with the middle text add an underscore followed by the 4 digit number .mp3

5. Find: (\w{1})(\w+),(\w+),(\d+.\d),(\d+) Replace: \1_\3,\5

• Find the first letter then rest of the word until a comma then the second word until comma then number with decimal comma and the final number

• Replace starting with first letter followed by an underscore and the second word then comma and the final number

6. Find: (\w{1})_(\w{4})(\w+),(\d+) Replace: \1_\2,\4

• Find the first single letter followed by an underscore then identify the first 4 letters of the first word then the rest of the word followed by a comma and number

• Replace with the first letter, underscore, then the first 4 letters followed by a comma and the number

7. Find: (\w{3})(\w+),(\w{3})(\w+),(\d+.\d),(\d+) Replace: \1\3, \6, \5

• Find the first three letters then the rest of the word until a comma, do the same of the next word. Then identify the number with a decimal and the second whole number seperated by a comma

• Replace with the first 3 letters of each word together with no space then comma followed by the whole number - comma - then the decimal number

8. Find: NA, Replace: 0,

• replace NA with 0

• I question my own decision here because NA does not necessarily equal zero but this felt more appropriate to the assignment than just deleting any row that contained NA

  
  Find: _ Replace: ~

• This is a step I applied only to the first line after trouble shooting removing special characters in the bombus_spp and host_plant columns. The tilde was not used anywhere else so would be easy to swap back after making other edits

  
  Find: [^,/.a-zA-Z\d\s\~:] Replace: blank

• Find any character that is NOT a comma, backslash, period, upper/lowercase letter, number, space, or tilde. Remove them.

  
  Find: \s, Replace: ,

• Find any commas with a space before them and remove the space

  
  Find: ~ Replace: _

• Replace the tildes in the first line that were used as a placeholder