如果未找到標題，會引發錯誤（csv文件）

Question

正在讀取CSV文件。如果以下列表中沒有任何標題，我想提出錯誤消息。它必須在csv文件中至少有一個標題。 插頭是 age sex city。我想這樣。謝謝

with open('data.csv') as f: 
    cf = csv.DictReader(f, fieldnames=['city']) 
    for row in cf: 
    print row['city'] 

Answer 1

這個怎麼樣？

import csv 

with open('data.csv', 'rb') as inf: 
    cf = csv.reader(inf) 

    header = cf.next() 
    if header != ['Age', 'Sex', 'City']: 
     print "No header found" 
    else: 
     for row in cf: 
      print row[2] 

Answer 2

在我對這個問題的理解中，如果找到任何頭文件，需要通過頭文件檢查。否則，它應該引發異常。

import csv 

with open('data.csv','rb') as f: 
    fieldnames = ['age','sex','city'] 
    cf = csv.DictReader(f) 
    headers = cf.fieldnames 

    if len(set(fieldnames).intersection(set(headers))) == 0: 
     raise csv.Error("CSV Error: Invalid headers: %s" % str(headers)) 

    for row in cf: 
     city = row['city'] if 'city' in headers else "N/A" 
     sex = row['sex'] if 'sex' in headers else "N/A" 
     age = row['age'] if 'age' in headers else "N/A" 
     print "city: " + city + ", sex: " + sex + ", age: " + age