Csv - 插入缺失的行

时间:2012-10-09 20:37:13

标签: python

我有一个巨大的文件,其中有一些丢失的行。数据需要植根于国家。

输入数据如下:

csv_str = """Type,Country,State,County,City,
1,USA,,,
2,USA,OH,,
3,USA,OH,Franklin,
4,USA,OH,Franklin,Columbus
4,USA,OH,Franklin,Springfield
4,USA,WI,Dane,Madison
"""

需要:

csv_str = """Type,Country,State,County,City,
1,USA,,,
2,USA,OH,,
3,USA,OH,Franklin,
4,USA,OH,Franklin,Columbus
4,USA,OH,Franklin,Springfield
4,USA,WI,,
4,USA,WI,Dane,
4,USA,WI,Dane,Madison
"""

根据我的逻辑关键字是Type字段,如果我找不到城市(类型4)的县(类型3),则插入一个字段到县的行。

与县相同。如果我找不到县(类型3)的州(类型2),则插入一行,其中字段最多为州。

由于我对python中的设施缺乏了解,我正在尝试更多的蛮力方法。这有点问题,因为我需要在同一个文件上进行大量迭代。

我也尝试了谷歌精炼,但无法让它工作。手动操作非常容易出错。

任何帮助表示感谢。

import csv
import io

csv_str = """Type,Country,State,County,City,
1,USA,,,
2,USA,OH,,
3,USA,OH,Franklin,
4,USA,OH,Franklin,Columbus
4,USA,OH,Franklin,Springfield
4,USA,WI,Dane,Madison
"""
found_county =[]
missing_county =[]

def check_missing_county(row):
    found = False
    for elm in found_county:
        if elm.Type == row.Type:
            found = True
    if not found:
        missing_county.append(row)
        print(row)

reader = csv.reader(io.StringIO(csv_str))
for row in reader:
    check_missing_county(row)

1 个答案:

答案 0 :(得分:1)

根据我对这个问题的理解,我已经敲了下面的内容:

import csv
import io

csv_str = u"""Type,Country,State,County,City,
1,USA,,,
2,USA,OH,,
3,USA,OH,Franklin,
4,USA,OH,Franklin,Columbus
4,USA,OH,Franklin,Springfield
4,USA,WI,Dane,Madison
"""

counties = []
states = []


def handle_missing_data(row):
    try:
        rtype = int(row[0])
    except ValueError:
        return []

    rtype = row[0]
    country = row[1]
    state = row[2]
    county = row[3]

    rows = []
    # if a state is present and it hasn't a row of it's own
    if state and state not in states:
        rows.append([rtype, country, state, '', ''])
        states.append(state)

    # if a county is present and it hasn't a row of it's own
    if county and county not in counties:
        rows.append([rtype, country, state, county, ''])
        counties.append(county)

    # if the row hasn't already been added add it now
    if row not in rows:
        rows.append(row)

    return rows

csvf = io.StringIO(csv_str)
reader = csv.reader(csvf)
for row in reader:
    new_rows = handle_missing_data(row)
    for new_row in new_rows:
        print new_row