Question

我正在尝试使用replace函数从列表中获取项目并将下面的字段替换为其相应的值，但是无论我做什么，它似乎只有在达到范围的末尾时才起作用（在i的最后一个可能值，它会成功替换子字符串，但在此之前不会）

    for i in range(len(fieldNameList)):
        foo = fieldNameList[i]
        bar = fieldValueList[i]
        msg = msg.replace(foo, bar)
        print msg

这是我运行该代码后得到的

<<name>> <<color>> <<age>>

<<name>> <<color>> <<age>>

<<name>> <<color>> 18

我对此坚持了太久了。任何建议将不胜感激。谢谢：）

完整代码：

def writeDocument():
    msgFile = raw_input("Name of file you would like to create or write to?: ")
    msgFile = open(msgFile, 'w+')
    msg = raw_input("\nType your message here. Indicate replaceable fields by surrounding them with \'<<>>\' Do not use spaces inside your fieldnames.\n\nYou can also create your fieldname list here. Write your first fieldname surrounded by <<>> followed by the value you'd like to assign, then repeat, separating everything by one space. Example: \"<<name>> ryan <<color>> blue\"\n\n")
    msg = msg.replace(' ', '\n')
    msgFile.write(msg)
    msgFile.close()
    print "\nDocument written successfully.\n"

def fillDocument():
    msgFile = raw_input("Name of file containing the message you'd like to fill?: ")
    fieldFile = raw_input("Name of file containing the fieldname list?: ")

    msgFile = open(msgFile, 'r+')
    fieldFile = open(fieldFile, 'r')

    fieldNameList = []
    fieldValueList = []
    fieldLine = fieldFile.readline()
    while fieldLine != '':
        fieldNameList.append(fieldLine)
        fieldLine = fieldFile.readline()
        fieldValueList.append(fieldLine)
        fieldLine = fieldFile.readline()

    print fieldNameList[0]
    print fieldValueList[0]
    print fieldNameList[1]
    print fieldValueList[1]
    msg = msgFile.readline()

    for i in range(len(fieldNameList)):
        foo = fieldNameList[i]
        bar = fieldValueList[i]
        msg = msg.replace(foo, bar)
        print msg

    msgFile.close()
    fieldFile.close()



###Program Starts#####--------------------

while True==True:
    objective = input("What would you like to do?\n1. Create a new document\n2. Fill in a document with fieldnames\n")
    if objective == 1:
        writeDocument()
    elif objective == 2:
        fillDocument()
    else:
        print "That's not a valid choice."

消息文件：

<<name>> <<color>> <<age>>

字段名称文件：

<<name>>
ryan
<<color>>
blue
<<age>>
18

Answer 1

原因：

这是因为除从“字段名”文件中读取的最后一行以外的所有行均包含“ \n”字符。因此，当程序进入替换部分fieldNameList时，fieldValueList和msg如下所示：

fieldNameList = ['<<name>>\n', '<<color>>\n', '<<age>>\n']
fieldValueList = ['ryan\n', 'blue\n', '18']
msg = '<<name>> <<color>> <<age>>\n'

因此replace（）函数实际上在msg字符串中搜索'<<name>>\n'，'<<color>>\n'，'<<age>>\n'，只有<<age>>字段被替换。（您必须有一个“ { {1}}”添加到msg文件的末尾，否则也将无法替换。）

解决方案：

在读取行时使用\n方法在结尾处去除换行符。

rstrip()

替换功能不适用于列表项

1 个答案: