Python 如何从类似矩阵的数据集中删除第一行和第一列

我已经使用R构造了特征向量矩阵，并将其输出到如下文件中：

"","values","vectors.1","vectors.2","vectors.3","vectors.4","vectors.5","vectors.6"
"1",5,0.49,0.40,-0.577,0,0.28,-0.4
"2",4,0,-0.40,0.283,0.5,0.577,-0.4
"3",3,-0.5,0.4,0.28,-0.5,0.28,-0.
"4",3,0.5,-0.4,0.28,-0.5,-0.28,-0.4
"5",1,-0.5,-0.4,-0.57,0,-0.28,-0.4
"6",0,0,0.4,0.28,0.5,-0.57,-0.4

我想删除第一行和第一列以提取矩阵本身并将其存储在另一个文件中（我相信您不能在打开的同一个文件中进行读写）。因此，我尝试了以下方法，但我不知道如何继续。谢谢你的帮助

with open('./test.csv', 'r') as csvfile, open('./output.csv', 'w') as outputfile:
    reader = csv.reader(csvfile, delimiter='\t')
    for line in reader:
        print line[0][3:]

---

您可以在不使用

CSV

模块的情况下读取和写入CSV文件。您可以遍历除第一行以外的所有行，然后将除第一行以外的每行的所有行写入输出文件，如下所示：

with open('./test.csv', 'r') as input_file, open('./output.csv', 'w') as output_file:
    for index, line in enumerate(input_file):
        if index != 0:
            output_file.write(",".join(line.split(",")[1:]))

---

让我知道这是否适用于您。

您可以使用以下方法：

new_file = open("new.csv", "a") # opens/creates new.csv to append the results
with open('old.csv') as f: # opens csv file for reading
    f.next() # skips the first line
    for line in f: # loop all lines in old.csv
        new_file.write(",".join(line.split(",")[1:])) # append to new.csv

new_file.close() # closes new.csv