CSV 讀取特定行

Question

我有一個包含 100 行的 CSV 文件。

如何讀取特定行？

我想讀說第 9 行或第 23 行等？

Answer 1

您可以使用list comprehension來過濾文件，如下所示：

with open('file.csv') as fd:
    reader=csv.reader(fd)
    interestingrows=[row for idx, row in enumerate(reader) if idx in (28,62)]
# now interestingrows contains the 28th and the 62th row after the header

Answer 2

使用list一次性抓取所有行作為列表。 然后通過列表中的索引/偏移量訪問目標行。 例如：

#!/usr/bin/env python

import csv

with open('source.csv') as csv_file:
    csv_reader = csv.reader(csv_file)
    rows = list(csv_reader)

    print(rows[8])
    print(rows[22])

Answer 3

您只需跳過必要的行數：

with open("test.csv", "rb") as infile:
    r = csv.reader(infile)
    for i in range(8): # count from 0 to 7
        next(r)     # and discard the rows
    row = next(r)   # "row" contains row number 9 now

Answer 4

您可以閱讀所有這些，然后使用普通列表來查找它們。

with open('bigfile.csv','rb') as longishfile:
    reader=csv.reader(longishfile)
    rows=[r for r in reader]
print row[9]
print row[88]

如果你有一個大文件，這會消耗你的內存，但如果文件少於 10,000 行，你不應該遇到任何大的減速。

Answer 5

你可以這樣做：

with open('raw_data.csv') as csvfile:
    readCSV = list(csv.reader(csvfile, delimiter=','))
    row_you_want = readCSV[index_of_row_you_want]

Answer 6

可能這可以幫助你，使用熊貓你可以很容易地用loc做到這一點

'''
Reading 3rd record using pandas -> (loc)
Note : Index start from 0 
If want to read second record then 3-1 -> 2
loc[2]` -> read second row and `:` -> entire row details 
'''

import pandas as pd
df = pd.read_csv('employee_details.csv')
df.loc[[2],:]

輸出 ：