问：TypeError：'_csv.reader' 对象不可调用

Question

我一直收到这个错误，谁能帮我解决这个问题？我在下面突出显示了有问题的代码行。我尝试将 reader 变量更改为 reader1，但问题仍然存在。

错误信息

Traceback（最近一次通话最后一次）：

文件“dna.py”，第 20 行，在

读者 = 读者（人物档案）

TypeError: '_csv.reader' 对象不可调用

**

• 我的代码

**

from sys import argv

from csv import reader, DictReader



if len(argv) < 3:

print("Wrong number of arguments")

exit()



#read the database file into memory

with open(argv[2]) as file:

reader = reader(file)

for row in reader:

dnalist = row



#create a variable containing the sample DNA

dna = dnalist[0]

#create a dictionary that holds the STR and the highest rep count

sequences = {}



with open(argv[1]) as peoplefile:

reader = reader(peoplefile) **<------ ERROR IS HERE**

for row in reader:

dnasequences = row

dnasequences.pop(0)

break

#set the STRs as keys in sequences dictionary

for i in dnasequences:

sequences[i] = 1



#Obtain the highest number of reps of each STR in the given DNA sequence

for key in sequences:

l = len(i)

tmp = 0

tmpmax = 0

#check

for i in dna:

if dna[i: i + l] == key:

tmp = 1

while dna[i:i+l] == dna[ i+l : i+2*l ]:

tmp += 1

i += l

if tmp > tmpmax:

tmpmax = tmp

sequences[key] = tmpmax



#Read database file into a dictionary

with open(argv[1]) as peoplefile:

reader = DictReader(peoplefile)

#loop through STR counts, comparing it to each person's STR counts

for person in reader:

match = 0

for i in sequences:

if sequences[i] == int(person(i)):

match += 1

#if all the highest STR reps match the person, print that person's name

if match == len(sequences):

print(row['name'])

exit()


print("Does not match any person")

Answer 1

当您尝试运行reader = reader(peoplefile) 时，它实际上是从您之前的代码行reader = reader(file) 中获取reader。

换句话说，您的错误行正在尝试运行如下内容：

reader = reader(file)(reader(peoplefile))

不要将函数的名称用作变量。使用csv_reader 作为变量而不是仅仅使用reader 可以解决问题。

...
# read the file into memory
with open(argv[2]) as file:    
    csv_reader = reader(file)    
    for row in csv_reader:    
        dnalist = row
...
with open(argv[1]) as peoplefile:
    csv_reader = reader(peoplefile)

编辑

我想出了一个例子来更好地解释发生了什么：

假设您有一个数字要转换为字符串，将其设置为一个名为 str 的新变量，然后打印它。

x = 279
str = str(x)
print(str)

此代码在语法上是正确的，但它可能会忽略代码的后面部分，例如，如果您有另一个数字并且还想将其转换为字符串并打印出来。

x = 279
str = str(x)
print(str)

y = 441
str = str(y)
print(str)    # TypeError here

使用与函数同名的变量名将覆盖该函数，并且下次您要调用该函数时实际上是在调用该变量。

第 2 部分

换个角度看，我认为例子越多越好：

只使用import csv 就可以了，所以你必须使用csv.reader() 来调用函数

import csv

with open('example.txt') as file:
    reader = csv.reader(file)
    for line in file:
        print(line)
    
with open('second_example_text.txt') as file:
    reader = csv.reader(file)
    for line in file:
        print(line)

在这种情况下，您可以根据需要多次使用reader，因为您不会覆盖函数csv.reader

希望有帮助！