csv

csv

csv parses and writes comma-separated values files (csv).

Functions

read_all(source, comma=",", comment="", lazy_quotes=False, trim_leading_space=False, fields_per_record=0, skip=0, limit=0) [][]string

read all rows from a source string, returning a list of string lists

Parameters

name	type	description
source	string	input string of csv data
comma	string	comma is the field delimiter, defaults to "," (a comma). comma must be a valid character and must not be \r, \n, or the Unicode replacement character (0xFFFD).
comment	string	comment, if not "", is the comment character. Lines beginning with the comment character without preceding whitespace are ignored. With leading whitespace the comment character becomes part of the field, even if trim_leading_space is True. comment must be a valid character and must not be \r, \n, or the Unicode replacement character (0xFFFD). It must also not be equal to comma.
lazy_quotes	bool	If lazy_quotes is True, a quote may appear in an unquoted field and a non-doubled quote may appear in a quoted field.
trim_leading_space	bool	If trim_leading_space is True, leading white space in a field is ignored. This is done even if the field delimiter, comma, is white space.
fields_per_record	int	fields_per_record is the number of expected fields per record. If fields_per_record is positive, read_all requires each record to have the given number of fields. If fields_per_record is 0, read_all sets it to the number of fields in the first record, so that future records must have the same field count. If fields_per_record is negative, no check is made and records may have a variable number of fields.
skip	int	Number of rows to skip before starting to read, omitting from returned rows.
limit	int	Maximum number of rows to read, stops reading when this limit is reached. If limit is 0, all rows after skip are read.

Examples

basic

read a csv string into a list of string lists

load("csv", "read_all")
data_str = """type,name,number_of_legs
dog,spot,4
cat,spot,3
spider,samantha,8
"""
data = read_all(data_str)
print(data)
# Output: [["type", "name", "number_of_legs"], ["dog", "spot", "4"], ["cat", "spot", "3"], ["spider", "samantha", "8"]]

skip_and_limit

read a csv string with skip and limit

load("csv", "read_all")
data_str = """type,name,number_of_legs
dog,spot,4
cat,spot,3
spider,samantha,8
"""
data = read_all(data_str, skip=1, limit=1)
print(data)
# Output: [["dog", "spot", "4"]]

write_all(source, comma=",") string

write all rows from source to a csv-encoded string

Parameters

name	type	description
source	[][]string	array of arrays of strings to write to csv
comma	string	comma is the field delimiter, defaults to "," (a comma). comma must be a valid character and must not be \r, \n, or the Unicode replacement character (0xFFFD).

Examples

basic

write a list of string lists to a csv string

load("csv", "write_all")
data = [
["type", "name", "number_of_legs"],
["dog", "spot", "4"],
["cat", "spot", "3"],
["spider", "samantha", "8"],
]
csv_str = write_all(data)
print(csv_str)
# Output: "type,name,number_of_legs\ndog,spot,4\ncat,spot,3\nspider,samantha,8\n"

write_dict(data, header, comma=",") string

write a list of dictionaries to a csv string based on the provided header

Parameters

name	type	description
data	[]dict	array of dictionaries where each dictionary is a row with field names as keys
header	[]string	array of strings representing the header (column names) of the csv
comma	string	comma is the field delimiter, defaults to "," (a comma). comma must be a valid character and must not be \r, \n, or the Unicode replacement character (0xFFFD).

Examples

basic

write a list of dictionaries to a csv string based on header

load("csv", "write_dict")
data = [
{"type": "dog", "name": "spot", "number_of_legs": 4},
{"type": "cat", "name": "spot", "number_of_legs": 3},
{"type": "spider", "name": "samantha", "number_of_legs": 8},
]
csv_str = write_dict(data, header=["type", "name", "number_of_legs"])
print(csv_str)
# Output: "type,name,number_of_legs\ndog,spot,4\ncat,spot,3\nspider,samantha,8\n"