CSV Writer只寫第一行文件

Question

所以我有專利數據，我希望從XML存儲到CSV文件。我已經能夠通過發明名稱，日期，國家和專利號碼的每次迭代運行我的代碼，但是當我嘗試將結果寫入CSV文件時出現問題。

的XML數據看起來像這樣（爲衆多的一個部分）：

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE us-patent-grant SYSTEM "us-patent-grant-v42-2006-08-23.dtd" [ ]> 
<us-patent-grant lang="EN" dtd-version="v4.2 2006-08-23" file="USD0584026-20090106.XML" status="PRODUCTION" id="us-patent-grant" country="US" date-produced="20081222" date-publ="20090106"> 
<us-bibliographic-data-grant> 
<publication-reference> 
<document-id> 
<country>US</country> 
<doc-number>D0584026</doc-number> 
<kind>S1</kind> 
<date>20090106</date> 
</document-id> 
</publication-reference> 

我通過一單通運行，寫這幾行代碼是：

for xml_string in separated_xml(infile): # Calls the output of the separated and read file to parse the data 
    soup = BeautifulSoup(xml_string, "lxml")  # BeautifulSoup parses the data strings where the XML is converted to Unicode 
    pub_ref = soup.findAll("publication-reference") # Beginning parsing at every instance of a publication 
    lst = [] # Creating empty list to append into 

    for info in pub_ref: # Looping over all instances of publication 

# The final loop finds every instance of invention name, patent number, date, and country to print and append into 

     with open('./output.csv', 'wb') as f: 
      writer = csv.writer(f, dialect = 'excel') 

      for inv_name, pat_num, date_num, country in zip(soup.findAll("invention-title"), soup.findAll("doc-number"), soup.findAll("date"), soup.findAll("country")): 
      #print(inv_name.text, pat_num.text, date_num.text, country.text) 
      #lst.append((inv_name.text, pat_num.text, date_num.text, country.text)) 
       writer.writerow([inv_name.text, pat_num.text, date_num.text, country.text]) 

最後，我的.csv文件中的輸出是這樣的：

"Content addressable information encapsulation, representation, and transfer",07475432,20090106,US 

我不確定問題出在哪裏，我知道我還是一個Python新手，但任何人都可以找到問題嗎？

Answer 1

您打開一個循環內覆蓋模式（'wb'）文件。在每次迭代中，您都會刪除以前寫過的內容。正確的方法是，打開外循環的文件：

... 
with open('./output.csv', 'wb') as f: 
    writer = csv.writer(f, dialect = 'excel') 

    for info in pub_ref: # Looping over all instances of publication 

# The final loop finds every instance of invention name, patent number, date, and country to print and append into 



     for inv_name, pat_num, date_num, country in zip(soup.findAll("invention-title"), soup.findAll("doc-number"), soup.findAll("date"), soup.findAll("country")): 
      ... 

Answer 2

的問題。如果你想所有的行寫入一個文件，使用模式a在於該行with open('./output.csv', 'wb') as f:

。使用wb將覆蓋該文件，因此您只能得到最後一行。

瞭解更多有關文件的方式在這裏：https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files