Python不追加到list

Question

我有一个以前使用过的脚本，它使用关键字列表来查询具有多个列和项的主文件。脚本应该逐行读取主文件，当遇到关键字时，它将整行写入新文件。

关键字文件如下:

A2M,ABCC9,ACADVL,ACTC1,ACTN2,ADA2,AGL

主文件看起来像这样:

8:27379821,8,27379821,[A/T],NM_001979,NM_001256482,NM_001256483,NM_001256484,A2M,A2M,A2M,A2M,,Silent,Silent,Silent,Silent
GSA-rs72475893,8,27380763,[A/G],NM_001979,NM_001256482,NM_001256483,NM_001256484,AM,AM,AM,AM,EXON,Missense_R1407W,Missense_R1307W,Missense_R1257W,Missense_R1407W
8:27381207,8,27381207,[A/C],NM_001979,NM_001256482,NM_001256483,NM_001256484,ADA2,ADA2,ADA2,ADA2,,Silent,Silent,Silent,Silent 
GSA-rs117056676,6,72385948,[T/C],,,,,AADACL2-AS1,AADAC,EXON,Silent,Silent,Missense_X400Q

期望的输出将是:

8:27379821,8,27379821,[A/T],NM_001979,NM_001256482,NM_001256483,NM_001256484,A2M,A2M,A2M,A2M,,Silent,Silent,Silent,Silent
8:27381207,8,27381207,[A/C],NM_001979,NM_001256482,NM_001256483,NM_001256484,ADA2,ADA2,ADA2,ADA2,,Silent,Silent,Silent,Silent

我使用的代码如下。我遇到的问题是"匹配"。列表变量看起来是空的，它没有附加任何东西。为什么会这样呢?它不匹配吗?还是因为它没有将它们添加到列表中?

我已经尝试使用主文件和关键字文件作为。csv和。txt，但没有工作。

谢谢你的帮助!

#open the list of words to search for
list_file = open(r'file.csv','r')
search_words = []
#loop through the words in the search list
for word in list_file:
#save each word in an array and strip whitespace
search_words.append(word.strip())
list_file.close()
#this is where the matching lines will be stored
matches = []
#open the master file
master_file = open(r'file2.csv','r')
#loop through each line in the master file
for line in master_file:
#split the current line into array, this allows for us to use the "in" operator to search for exact strings
current_line = line.split()
#loop through each search word
for search_word in search_words:
#check if the search word is in the current line
if search_word in current_line:
#if found then save the line as we found it in the file
matches.append(line)
#once found then stop searching the current line
break
master_file.close()
#create the new file
new_file = open(r'file3.txt', 'w')
#loop through all of the matched lines
for line in matches:
#write the current matched line to the new file
new_file.write(line)
new_file.close()

Answer 1

我尝试添加两个print语句来查看幕后发生了什么，并发现您正在阅读的第一个文件没有将句子分成单独的单词。

search_words的存储方式如下:

search_words = ['hello this is a line']

而不是像这样

search_words = ['hello', 'this', 'is', 'a', 'line']

我修改了第10行

到此:search_words += (word.strip()).split()而不是:search_words.append(word.strip())

下面是修改后的代码:

#open the list of words to search for
list_file = open(r'file.csv','r')
search_words = []
#loop through the words in the search list
for word in list_file:
#save each word in an array and strip whitespace
search_words += (word.strip()).split()
list_file.close()
#print (search_words)    
#this is where the matching lines will be stored
matches = []
#open the master file
master_file = open(r'file2.csv','r')
#loop through each line in the master file
for line in master_file:
#split the current line into array, this allows for us to use the "in" operator to search for exact strings
current_line = line.split()
#print (current_line)
#loop through each search word
for search_word in search_words:
#check if the search word is in the current line
if search_word in current_line:
#if found then save the line as we found it in the file
matches.append(line)
#once found then stop searching the current line
break
master_file.close()
#create the new file
new_file = open(r'file3.txt', 'w')
#loop through all of the matched lines
for line in matches:
#write the current matched line to the new file
new_file.write(line)
new_file.close()

Answer 2

有两个问题一目了然:

在文件上迭代将得到行，而不是在,字符上分割。在使用.strip()和添加到搜索列表之前，您需要使用.split()。因为您的示例输入只有一行，所以我删除了每行的迭代，但是如果您希望有多行，可以很容易地将其添加回去。

第二，默认情况下，.split()将在(一个空格)上分割，而不是,，因此您需要将其指定为.split()的参数。

通过这些修复(并使用上下文打开文件)，修复的代码是:

search_words = []
with open(r'file.csv','r') as list_file:
for word in list_file.read().split(","):  # Fix 1
search_words.append(word.strip())
matches = []
with open(r'file2.csv','r') as master_file:
for line in master_file:
# Not strictly necessary, we can search in the string using in
current_line = line.split(",")   # Fix 2
for search_word in search_words:
if search_word in current_line:
matches.append(line)
break
with open(r'file3.txt', 'w') as new_file:
for line in matches:
new_file.write(line)
print(line)

结果:

8:27379821,8,27379821,[A/T],NM_001979,NM_001256482,NM_001256483,NM_001256484,A2M,A2M,A2M,A2M,,Silent,Silent,Silent,Silent
8:27381207,8,27381207,[A/C],NM_001979,NM_001256482,NM_001256483,NM_001256484,ADA2,ADA2,ADA2,ADA2,,Silent,Silent,Silent,Silent 

(注意控制台输出在每行之间有额外的新行)