Delimited (CSV) files: structure
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. In a CSV file, how is each record stored?
2. Which line is a valid CSV record with three fields?
3. What is the job of the delimiter character in a CSV file?
4. What does the optional header row contain?
5. A CSV file has a header row plus 5 lines of data. How many records does it store?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1name,year,house | AOne record on a single line, with three fields separated by commas | |
| 2Ava,7,Red | BAva;7;Red | |
| 3Text that contains a comma is wrapped in double quotes so the comma is not treated as a delimiter | CA header row: the first line lists the field names, separated by commas | |
| 4A delimiter other than a comma, such as a semicolon, can separate the fields in a delimited file | D"Nguyen, Ava",7,Red | |
| 5Nguyen, Ava,7,Red | EThe comma inside the name is not quoted, so it is read as a delimiter and the line splits into four fields instead of three. Fix: "Nguyen, Ava",7,Red | |
| 6name,year,house Ava,7,Red | FThe header and the record are on the same line. Each record must be on its own line, so the header and the record need a line break between them. |
C
Definitions
CSV
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
fields = line._____(",")
2.
delimiter = ";"
fields = line.split(_________)
3.
header = lines[_]
records = lines[1:]
4.
recordCount = len(lines) _ 1
5.
line = ",".____(fields)
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
name,age,house
B
Ava,15,Red
C
Liam,16,,Blue
Question 2
A
id,name,score
B
1;Ava;90
C
2,Liam,85
Question 3
A
item,price,note
B
Pen,2.5,"blue, fine tip"
C
Book,12,red, hardcover
Question 4
A
name,age,year
B
Zoe,14,9
C
Leo,15
D
Mia,13,8
Question 5
A
name,age
B
Ava,15,Perth
C
Liam,16,Hobart
Answer Key
Delimited (CSV) files: structure
Section A: Quick Questions
Q1
A — One record per line
Q2
B — Ava,16,Melbourne
Q3
A — It separates one field from the next
Q4
B — The names of the fields
Q5
A — 5 records
Section B: Match the Pairs
Q1
name,year,house → A header row: the first line lists the field names, separated by commas
Q2
Ava,7,Red → One record on a single line, with three fields separated by commas
Q3
Text that contains a comma is wrapped in double quotes so the comma is not treated as a delimiter → "Nguyen, Ava",7,Red
Q4
A delimiter other than a comma, such as a semicolon, can separate the fields in a delimited file → Ava;7;Red
Q5
Nguyen, Ava,7,Red → The comma inside the name is not quoted, so it is read as a delimiter and the line splits into four fields instead of three. Fix: "Nguyen, Ava",7,Red
Q6
name,year,house Ava,7,Red → The header and the record are on the same line. Each record must be on its own line, so the header and the record need a line break between them.
Section C: Definitions
Q1
CSV — A text file with one record per line, fields split by a delimiter such as a comma, and an optional header line of field names. Text containing commas goes in quotes.Section D: Fill in the Blanks
Q1
fields = line.split(",")Q2
delimiter = ";"
fields = line.split(delimiter)Q3
header = lines[0]
records = lines[1:]Q4
recordCount = len(lines) - 1Q5
line = ",".join(fields)Section E: Spot the Error
Q1
C — The double comma creates an extra empty field, so this record has 4 fields while the header has 3. It should be Liam,16,Blue.
Q2
B — The header uses commas as the delimiter, so every record must too. Semicolons would make the whole line read as one field. It should be 1,Ava,90.
Q3
C — The note contains a comma, so it must be wrapped in double quotes. Without them the line splits into 4 fields. It should be Book,12,"red, hardcover".
Q4
C — The header has 3 fields, so every record needs 3 fields. This record is missing the year. It should be Leo,15,10.
Q5
A — The header row must list a name for every field in the records. The records have 3 fields but the header names only 2. It should be name,age,city.