我想读取csv文件中的x列并根据x列中的内容填充其他列？ 如何在Python中做到这一点？

Question

I have a csv file. A column x has string values. Based on the values in the column x , I want to populate other columns in a different csv. how do I do that?

Answer 1

you might be able to do something like this if you pass to the function a line number an a column number

def readCSVfile(line, column):
    fp = open("file")
    for i, line in enumerate(fp):
        if i == line-1:
            res = line.split(',')
    fp.close()
    return res[column]

Answer 2

My answer addresses the problem of processing a column of your data and writing a NEW file to save the results of processing.

The following code has inline comments that, I hope, will clarify its innards.

# processing csv files is simple
# but there are lots of details that can go wrong,
# let's use a builtin module
import csv

# to abstract your (underspecified) problem, let's assume that
# we have defined what we want to do to our data in terms
# of a set of functions
from my_module import f0, f1, f2, ..., fn

# let's define a bunch of constants, in real life these should rather be
# command line arguments
input = './a/path/name.csv'a
out = './anothe/r_path/name.csv'
index_x = 5

# slurp in the data
with f as open(input):
    data = [row for row in csv.reader(f)]

# transpose the data — list(...) is necessary for python 3
# where zip() returns a generator
data = list(zip(*data))

# extract the data
x = data[index_x]

# the data processing is done with a double loop,
# the outer loop on x values,
#    the inner loop on the processing units (aka the imported functions)
processed = [[f(item)]  for item in x for f in [f0, f1, f2, ..., fn]]

# eventually, output the results of our computations to a different csv file
# using the writerows() method that nicely iteratates on the rows of its
# argument in our behalf
with f as open(out, 'w'):
    csv.writer(f).writerows(processed)