替换列表中的索引字符串并写入文本文件

Question

我正在尝试替换文本文件中的某些单词（基本上是每行的第二个单词），然后将它们写回新文件或覆盖现有文件。

我以为我正在取得进展，但是当我去写入一个新文件时，我收到一条错误消息，说我无法将列表写入文本文件。我不能简单地将一个单词替换为另一个单词，因为我有一个“else”子句，它涵盖了与我需要替换的其他单词不匹配的任何单词。

这是我尝试修改的文本示例，该文本包含在 .txt 文件中：

id int,
organization_id int,
billing_month date,
fee_type varchar(100),
rate float,
price float,
uom varchar(25),
amount float,
currency_code_id float,
process_ts timestamptz NOT NULL DEFAULT (now())::timestamptz(6)

我想改变：

'int' --> 'BIGINT'
'numeric' --> 'DOUBLE'
'float' --> 'DOUBLE'
ELSE other data type --> 'STRING' .  

在原始数据中，请注意有些还有其他字符，例如“varchar(100)” - 我想用“STRING”替换这些字符并删除“(100)”部分。

然后覆盖或创建一个新的文本文件。因此，如果正确替换，上述示例输出将是：

id BIGINT,
organization_id BIGINT,
billing_month STRING,
fee_type STRING,
rate DOUBLE,
price DOUBLE,
uom STRING,
amount DOUBLE,
currency_code_id DOUBLE,
process_ts STRING

我不知道是否应该创建列表，然后修改它们，然后将这些列表写入文本文件、字典或其他我没有想到的方法。我是一个初学者，如果这不是很清楚，请道歉。

Answer 1

txt.txt 的内容：

id int,
organization_id int,
billing_month date,
fee_type varchar(100),
rate float,
price float,
uom varchar(25),
amount float,
currency_code_id float,
process_ts timestamptz NOT NULL DEFAULT (now())::timestamptz(6)

代码：

with open('txt.txt', 'r') as f:
    text = f.read().splitlines()

mapping = {'int':'BIGINT',
           'numeric':'DOUBLE',
           'float':'DOUBLE'}

replaced_text = []
for line in text:
    # temporarily remove comma
    line = line.rstrip(',')
    split_line = line.split()
    other_text, dtype = split_line[0], split_line[1:]
    new_dtype = mapping.get(' '.join(dtype), 'STRING')
    new_line = '{} {},\n'.format(other_text, new_dtype)
    replaced_text.append(new_line)


with open('txt_replaced.txt', 'w') as f:
    f.writelines(replaced_text)

txt_replaced.txt 的内容：

id BIGINT,
organization_id BIGINT,
billing_month STRING,
fee_type STRING,
rate DOUBLE,
price DOUBLE,
uom STRING,
amount DOUBLE,
currency_code_id DOUBLE,
process_ts STRING,

Answer 2

您可以遍历每一行并使用字典替换每行第二个位置的值。这适用于任何长度的行，只要要替换的文本是第二个单词。

#vals to replace
replace_vals = {'int':'BIGINT', 'numeric':'DOUBLE', 'float':'DOUBLE'}

#file we write to
with open('out.txt', 'w') as outfile:
  #file we read from
  with open ("in.txt", 'r') as infile:
    #check each line
    for line in infile:
      #split line into words
      words = line.split()
      #get the first word and then replace the second word, defaulting to STRING
      w = words[0] + " " + replace_vals.get(words[1], 'STRING')
      #add a final newline
      w += "\n"
      #print to file
      outfile.write(w)

Demo

Answer 3

也许这样的事情可以帮助你：

import os, sys
from re import match as regexSearch

path = os.path.dirname(__file__)
myFile = open(os.path.join(path, "filename.txt"), "r")

regExpr = r"[\w_]+ ([\w\(\)\d:]+)(,|\s)"


with open(os.path.join(path, "newFile.txt"), "w") as f:
    for line in myFile.readlines():
        match = regexSearch(regExpr, line)
        if match:
            result = match.group(1)
            if "int" in result:
                f.write(line.replace(result, "BIGINT"))
            elif result in ["numeric", "float"]:
                f.write(line.replace(result, "DOUBLE"))
            else:
                f.write(line.replace(result, "STRING"))
        else:
            print("couldn't find something in line:\n", line)
    f.close()