Python - For 循环不会用它的匹配值替换每个字典键......只合作字典中的最后一个键和值

Question

So I have some code to make a module and I need help utilizing a for loop with .replace() in it. The problem is that when I loop through variables , and use .replace(k, v) , my code will only replace the last key with it's matching last value in the dictionary. This leaves all the previous keys left in the output without being replaced with their matching value... I need every key to be replaced with every value, and it will only comply by doing the last key in the dict

variables = {'font1': 'Harlow Solid', 'grey': '#454545', 'font2': 'mistral'}

style_sheet ='''/* Pyle Sheets */
hashone{
    font: Italic 70px font1;
}
hashtwo{                       # scroll down to see 'for' loop in question
    font: bold 45px font2;     # scroll down to see 'for' loop in question
}
hashthree{
    font: Italic 25px Harlow Solid;
}
dotsample{
    text-align: center;
}
hashbodyid{
    background: grey;
}
'''
replace_num = len(variables.keys()) # <--for loop/.replace(k, v) function
for k, v in variables.items():      # <--for loop/.replace(k, v) function
    content = style_sheet.replace(k, v, replace_num) # <--- here it is...

looped_content = str(content)
id_content = looped_content.replace("hash", "#")
clss_idContent = id_content.replace("dot", ".")
#------------
print(clss_idContent) # view output

Answer 1

在替换的源字符串（ style_sheet ） style_sheet您在循环中一次又一次地覆盖content 。

Answer 2

There is a logical mistake in your code. Let's analyze your code.

Suppose style_sheet equals to aabbcc , and variables equals to {"a": 1, "b" : 2, "c": 3} .

What will happen during loop?

First loop: content = "aabbcc".replace("a", 1, 3) , so content = "11bbcc" .

Second loop: content = "aabbcc".replace("b", 2, 3) , so content = "aa22cc" .

Last loop: content = "aabbcc".replace("c", 3, 3) , so content = "aabb33" .

So do you notice where is the key point?

You should update original string during every loop too!

You can change your code like the following:

content = style_sheet
for k, v in variables.items():
    content = content.replace(k, v, replace_num)  #update original string

Answer 3

What you could do in the loop is instead of setting it to a variable you could append it to aa list, or do update on a dictionary.

For instance, since looped_content is a string, you could initialize it before the loop and append content to it each time in the loop. Or if it is a dict, update it. This would prevent content from being overwritten each time, as mentioned by another poster.

looped_content = ""



replace_num = len(variables.keys()) # <--for loop/.replace(k, v) function
for k, v in variables.items():      # <--for loop/.replace(k, v) function
    content = style_sheet.replace(k, v, replace_num) # <--- here it is...
    looped_content.append(content)

id_content = looped_content.replace("hash", "#")
clss_idContent = id_content.replace("dot", ".")