Python - Way to recursively find and replace string in text files

Question

I want to recursively search through a directory with subdirectories of text files and replace every occurrence of {$replace} within the files with the contents of a multi l

Answer 1

Sulpy's answer is good but incomplete. The user would be likely to want to input the parameters through an entry widget, so we might have something more like this (also incomplete, but left as an exercise):

import os, fnmatch
from Tkinter import *
fields = 'Folder', 'Search', 'Replace', 'FilePattern'

def fetch(entvals):
#    print entvals
#    print ents
    entItems = entvals.items()
    for entItem in entItems:
        field = entItem[0]
        text  = entItem[1].get()
        print('%s: "%s"' % (field, text))

def findReplace(entvals):
#    print ents
    directory = entvals.get("Folder").get()
    find = entvals.get("Search").get()
    replace = entvals.get("Replace").get()
    filePattern = entvals.get("FilePattern").get()
    for path, dirs, files in os.walk(os.path.abspath(directory)):
        for filename in fnmatch.filter(files, filePattern):
#            print filename
            filepath = os.path.join(path, filename)
            print filepath  # Can be commented out --  used for confirmation
            with open(filepath) as f:
                s = f.read()
            s = s.replace(find, replace)
            with open(filepath, "w") as f:
                f.write(s)

def makeform(root, fields):
    entvals = {}
    for field in fields:
        row = Frame(root)
        lab = Label(row, width=17, text=field+": ", anchor='w')
        ent = Entry(row)
        row.pack(side=TOP, fill=X, padx=5, pady=5)
        lab.pack(side=LEFT)
        ent.pack(side=RIGHT, expand=YES, fill=X)
        entvals[field] = ent
#        print ent
    return entvals

if __name__ == '__main__':
    root = Tk()
    root.title("Recursive S&R")
    ents = makeform(root, fields)
#    print ents
    root.bind('', (lambda event, e=ents: fetch(e)))
    b1 = Button(root, text='Show', command=(lambda e=ents: fetch(e)))
    b1.pack(side=LEFT, padx=5, pady=5)
    b2 = Button(root, text='Execute', command=(lambda e=ents: findReplace(e)))
    b2.pack(side=LEFT, padx=5, pady=5)
    b3 = Button(root, text='Quit', command=root.quit)
    b3.pack(side=LEFT, padx=5, pady=5)
    root.mainloop()