Sed with python and many parameters

Question

I have a big file with some lines like:

Users.txt

• User1:jhonny
• User2:Mary
• User3:Jane

And another file with:

Data.txt

• User1:Brown
• User3:Yellow
• User2:Green

I want to make just one file, replacing the first field of Data.txt with the second field in Users.txt. On the final, it may look like this:

Final.txt

• Jhonny:Brown
• Jane:Yellow
• Mary:Green

I have made the following code in python.

with open("File", "r") as sources:
    lines = sources.readlines()
with open("File", "w") as sources:
    for line in lines:
        sources.write(re.sub(r'TextToReplace', 'ParameterToReplace', line))

I need to replace TextToReplace with the first field on the file Users.txt and the ParameterToReplace is the second field on Users.txt. Many times, with 30M+ parameters.

It's like a command sed 's/TextToReplace/ParameterToReplace/" File

• TextToReplace = The old text to be replaced.
• ParameterToReplace = The new text.

Answer 1

you can use dict if data has mixed:

userdict={}
for i in open("users.txt","r").read().split("\n"):
    arr=i.split(":")
    userdict[arr[0]]=arr[1]
with open("final.txt","w") as f:
    for i in open("data.txt","r").read().split("\n"):
        arr=i.split(":")
        f.write("{}:{}".format(userdict[arr[0]],arr[1]))

Answer 2

The join command is useful for this kind of thing. Assuming your shell understands Process Substitutions:

$ join -o 1.2,2.2 -t: <(sort users.txt) <(sort data.txt)
jhonny:Brown
Mary:Green
Jane:Yellow