Python - CSV 활용

CSV Data 읽고 쓰기(Reading & Writing CSV Data)

읽기(Reading)

stocks.csv

stocks.csv
Symbol,Price,Date,Time,Change,Volume
"AA",39.48,"6/11/2007","9:36am",-0.18,181800
"AIG",71.38,"6/11/2007","9:36am",-0.15,195500
"AXP",62.58,"6/11/2007","9:36am",-0.46,935000
"BA",98.31,"6/11/2007","9:36am",+0.12,104800
"C",53.08,"6/11/2007","9:36am",-0.25,360900
"CAT",78.29,"6/11/2007","9:36am",-0.23,225400

csv library 사용

import csv
with open('stocks.csv') as f:
    f_csv = csv.reader(f)
    headers = next(f_csv)
    for row in f_csv:
        # Process row
        #print(row)
        print('basic : %s %s ' % (row[0], row[4]))

• row 는 list 자료형

• 인덱싱으로 자료 처리(indexing)

• row[0] (Symbol) and row[4] (Change).

• 인덱싱은 종종 혼동을 일으킴

namedtuple 사용

import csv
from collections import namedtuple
with open('stocks.csv') as f:
    f_csv = csv.reader(f)
    headings = next(f_csv)
    Row = namedtuple('Row', headings)
    for r in f_csv:
        row = Row(*r)
        # Process row
        #print(row)
        print('Row : %s %s ' % (row.Symbol, row.Change))

• row.Symbol and row.Change

• use of column headers

csv.DictReader 사용

import csv
with open('stocks.csv') as f:
    f_csv = csv.DictReader(f)
    for row in f_csv:
        # process row
        #print(row)
        print('OrderedDict : %s %s ' % (row['Symbol'], row['Change']))

• row['Symbol'] or row['Change'].

DictReader를 이용한 데이터 출력 확인

쓰기(Writing)

csv.writer 사용

csv.writer 사용

csv.DictWriter 사용

csv.DictWriter 사용