查找，重新格式化並替換字符串中的多個日期

Question

我有一個很長的字符串包含日期，並希望更新所有日期的格式。

以下是我與位的僞代碼我想不通一起寫入：

import datetime 

current_date_format = "%d/%m/%Y" 
new_date_format = "%d/%b/%Y" 

def main(): 
    line = "This is text dated 01/02/2017, and there are a few more dates such as 03/07/2017 and 09/06/2000" 
    print(line) 
    # Best way to pull out and replace all of the dates? 
    # pseudo: 
    for each current_date_format in line as date_in_line 
     temp_date = fix_date(date_in_line) 
     line.replace(date_in_line, temp_date) 
    print(line) 

def fix_date(date_string=''): 
    return datetime.datetime.strptime(date_string, current_date_format).strftime(new_date_format) 

在這種情況下，如果要打印：

This is text dated 01/02/2017, and there are a few more dates such as 03/07/2017 and 09/06/2000 
This is text dated 01/FEB/2017, and there are a few more dates such as 03/JUL/2017 and 09/JUN/2000 

感謝

Answer 1

第一建議不是一個完整的解決方案，請跳至下面的第一個編輯部分

如果你想用幾種方式調整你的代碼，你可以這樣做。最初只是打出來的字符串成片：

line = "This is text dated 01/02/2017, and there are a few more dates such as 03/07/2017 and 09/06/2000" 
words = line.split() # by default it splits on whitespace 

現在，您可以與您的各項輸入的發揮。然後，您可以嘗試使用您的fix_date方法來解析您的日期，並重新編譯字符串：

updated_line = '' 
for word in words: 
    try: 
     updated_line += fix_date(word) + ' ' 
    except: 
     updated_line += word + ' ' 
updated_line = updated_line[:-1] # gets rid of the extra trailing space 
print(updated_line) 

編輯：跑步時我意識到這個具有安裝日期標點符號的問題。我正在再次傳球。

下面是一些工作代碼：

import datetime 
import re 

current_date_format = "%d/%m/%Y" 
new_date_format = "%d/%b/%Y" 

def main(): 
    line = "This is text dated 01/02/2017, and there are a few more dates such as 03/07/2017 and 09/06/2000" 
    print(line) 
    line = re.sub(r'\d{2}/\d{2}/\d{4}',fix_date,line) 
    print(line) 

def fix_date(rem): 
    date_string = rem.group() 
    return datetime.datetime.strptime(date_string, current_date_format).strftime(new_date_format) 

main() 

編輯2：作爲正則表達式的方法適用於龐大的字符串儘可能小的，如果你的文件尺寸很小，足以載入一下子就可以只是做了一個鏡頭：

import datetime 
import re 

current_date_format = "%d/%m/%Y" 
new_date_format = "%d/%b/%Y" 

def main(): 
    with open('my_file.txt','r') as f: 
     text = f.read() 
    with open('my_fixed_file.txt','w') as f: 
     f.write(re.sub(r'\d{2}/\d{2}/\d{4}',fix_date,text)) 

def fix_date(rem): 
    date_string = rem.group() 
    return datetime.datetime.strptime(date_string, current_date_format).strftime(new_date_format) 

main() 

甚至更​​緊湊，通過調整文件讀取/寫入部：

... 
with open('my_file.txt','r') as f: 
    with open('my_fixed_file.txt','w') as f2: 
     f2.write(re.sub(r'\d{2}/\d{2}/\d{4}',fix_date,f.read())) 
...