读取csv文件并将字符转化为float

我要把csv文件中的字符转为浮点数，报错说我没有定义文件名

import numpy as np
import pandas as pd

data=pd.read_csv('C:/Users/94402/Desktop/green.csv',encoding='gbk')
print(data)

import codecs
from csv import reader
def load_csv(green):
    dataset = list()
    with open(green,'r') as file:
        csv_reader = reader(file)
        headings = next(csv_reader)
        for row in csv_reader:
            if not row:
                continue
            dataset.append(row)
    return dataset

def str_column_to_float(dataset, column):
    for row in dataset:
        row[column] = float(row[column].strip())

filename='insurance.csv'
**dataset = load_csv(green)**//这一行报错name 'green' is not defined
print('读取后',dataset)
for col in range(len(dataset[0])):
    str_column_to_float(dataset,col)
print('转化后',dataset)

实在不懂

green没有定义呀，green是函数的参数名称。这里应该是filename