CODEWITHSUNDEEP
pythonpython-3.xcsv
MH Yen
MH Yen

Reputation: 43

How to make strings into a list?

I try to edit one of the column data into the format I want by using csv.DictReader(), the code is like this:

import csv
import time
with open('201701.csv') as inf:
        reader = csv.DictReader(inf)
        for row in reader:
            date = row['日期']
            d = date.split('/')
            year = int(d[0]) + 1911
            month = str(d[1])
            day = str(d[2])
            date_ = str(year) + "{0:2}".format(month) + "{0:2}".format(day)
            print(date_)

the outcome is like this: 

20170103
20170104
20170105
20170106
20170109
20170110
20170111
20170112
20170113
20170116
20170117
20170118
20170119
20170120
20170123
20170124

But I want the data in the way like this:

date_list = ['20170103', '20170104', '20170105', '20170106', '20170109', '20170110', '20170111', '20170112', '20170113', '20170116', '20170117', '20170118', '20170119', '20170120', '20170123', '20170124']

Upvotes: 1

Views: 88

Answers (3)

mhawke
mhawke

Reputation: 87134

You could write it as a generator. This gives you the ability to iterate over the sequence of dates from the file, or collect them together in a list. I have simplified your code :

import csv
import time

def get_dates(inf):
    for row in csv.DictReader(inf):
        year, month, day = row['日期'].split('/')
        yield '{}{:02}{:02}'.format(int(year) + 1911, int(month), int(day))

Usage:

# Collect into a list
with open('201701.csv') as inf:
    date_list = list(get_dates(inf))
    print(date_list)

# Or iterate over the dates
with open('201701.csv') as inf:
    for date in get_dates(inf):
        print(date)

Upvotes: 1

Jeremy McGibbon
Jeremy McGibbon

Reputation: 3785

Well, if you want a date_list then you should make one!

import csv
import time
date_list = []
with open('201701.csv') as inf:with open('201701.csv') as inf:
    reader = csv.DictReader(inf)
    for row in reader:
        date = row['日期']
        d = date.split('/')
        year = int(d[0]) + 1911
        month = str(d[1])
        day = str(d[2])
        date_ = str(year) + "{0:2}".format(month) + "{0:2}".format(day)
        print(date_)
        date_list.append(date_)
print(date_list)

Upvotes: 0

malioboro
malioboro

Reputation: 3301

Your output is like that because you print a single string date using print(date_) iteratively. That is not a list at all.

To make a list, append your date string to a list date_list:

import csv
import time
date_list = []    # create list of date
with open('201701.csv') as inf:with open('201701.csv') as inf:
        reader = csv.DictReader(inf)
        for row in reader:
            date = row['日期']
            d = date.split('/')
            year = int(d[0]) + 1911
            month = str(d[1])
            day = str(d[2])
            date_ = str(year) + "{0:2}".format(month) + "{0:2}".format(day)
            date_list.append(date_)  # append your date string to list
print(date_list)

Upvotes: 1

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