csv 文件有问题用 csv.reader 打开它

Question

I have the following code:

import pandas as pd
import numpy as np
import csv
filename = (r"C:\Users\Z\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Anaconda3 (64- bit)\diabetes.csv")
raw_data = open(filename, 'rb')
reader = csv.reader(raw_data, delimiter=',', quoting=csv.QUOTE_NONE)
x = list(reader)
data = (np.array(x)).astype('float')
print(data.shape)

But it errors:

----> 7 x = list(reader)
Error: iterator should return strings, not bytes (did you open the file in text mode?)

When I change 'rb' to 'rt' :

raw_data = open(filename, 'rt')

It says:

----> 8 data = (np.array(x)).astype('float')
ValueError: could not convert string to float: 'Pregnancies'

And when I delete .astype('float') , the result is (769, 9) but the expected result is (768, 9) .

It counts the header as data. Can you tell me why?

Answer 1

The error is in your mode of opening the file. You opened the file in 'rb' mode. 'rb' is used only for binary files and CSV file type is not binary.

Use:

raw_data = open(filename, 'r')

OR

raw_data = open(filename)

This is because the file is by default opened in read mode by open() function.

And about header being taken as data, use

reader = csv.reader(file, delimiter = ','[,other parameters])
data = []
for i in reader:
  if i[0] = "You first cell's data":
    pass
  else:
    data.append(i)

Now you can use the list to create Numpy Arrays

Answer 2

Before you do following:

reader = csv.reader(raw_data, delimiter=',', quoting=csv.QUOTE_NONE)
x = list(reader)

try

reader = csv.reader(raw_data, delimiter=',', quoting=csv.QUOTE_NONE)
next(reader)
x = list(reader)

which should skip the header of csvfiles.

It is described @ https://docs.python.org/3/library/csv.html#csv.csvreader.__next_ _