line_edit.setInputMask("999,999,999,999.99")

line_edit.setValidator(QtGui.QDoubleValidator(0, 999999999999.99, 2, line_edit))

# -*- coding: utf-8 -*-
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import PyQt4.Qt
import sys

def tran(num, pic):
    if len(pic)==0: return num
    out=""
    outdec=""
    #уберем не цифры
    newnum=""
    for i in num:
        if str(i) in "-0123456789.": newnum+=i
    num=newnum
    if "." in num:#делим число
        dec=num.split(".")[1]
        num=num.split(".")[0]
    else: dec=""
    if "." in pic:#делим шаблон
        picdec="."+pic.split(".")[1]
        pic=pic.split(".")[0]
    else: picdec=""
    #делим целые
    j=len(num)-1
    for i in range(len(pic)-1,-1 ,-1):
        if j>=0:
            if pic[i]=="9":
                out=num[j]+out
                j-=1;
            else:
                out=pic[i]+out
    #делим десятые
    j=0
    for i in range(0, len(picdec)):
        if picdec[i]=="9":
            if j<len(dec):
                outdec+=dec[j]
                j+=1;
            else:
                outdec+="0";
        else:
            outdec+=picdec[i]
    return out+outdec


class zzLineEdit(QLineEdit):
    type="lineedit"
    def __init__(self, txt="",pic=""):
        txt=u"%s" % txt
        self.pic=pic.strip()
        if self.pic<>"":
            txt=tran(txt, pic)
            if "." in self.pic:
                self.DECIMAL_POINT_POS=len(self.pic.split(".")[1])
            else:
                self.DECIMAL_POINT_POS=0
        QLineEdit.__init__(self, txt)
        if self.pic<>"":
            self.setAlignment(Qt.AlignRight)
            self.textEdited.connect(self.on_textEdited)
        self.escapePressed=False
    def event(self, ev):
        if ev.type()==QEvent.ShortcutOverride:
            if ev.key()==Qt.Key_Escape:
                self.escapePressed=True
        return QLineEdit.event(self, ev)
    def keyPressEvent(self, ev):
        if ev.key() in [Qt.Key_Enter, Qt.Key_Return]:
            ev.accept()
            self.focusNextChild()
        else:
            if self.pic<>"": self.picMake(ev)
            else: QLineEdit.keyPressEvent(self, ev)
    def on_textEdited ( self,  _txt ) :
        prevtext=QLineEdit.text(self)
        cur_pos_left=len(prevtext)-self.cursorPosition()
        self.setText(tran(_txt.replace(",", ""), self.pic))
        if QLineEdit.text(self)=="."+"0"*self.DECIMAL_POINT_POS: cur_pos_left=len(QLineEdit.text(self))
        if cur_pos_left>self.DECIMAL_POINT_POS:
            self.setCursorPosition (len(QLineEdit.text(self))-cur_pos_left)
        else:
            self.setCursorPosition (len(QLineEdit.text(self))-cur_pos_left+1)
    def setText(self, txt):
        if len(self.pic)>0: txt=tran(txt, self.pic)
        QLineEdit.setText(self, txt)
    def valid(self): return True
    def text(self):
        txt=QLineEdit.text(self)
        if len(self.pic)==0: return txt
        #уберем не цифры
        newnum=""
        for i in txt:
            if str(i) in "-0123456789.":newnum+=i
        return newnum
    def picMake(self, event):
        key = event.key()
        text=str(QLineEdit.text(self))
        selected_text=self.selectedText()
        curpos=self.cursorPosition()
        was_modifiers=False if event.modifiers() in [Qt.NoModifier,Qt.KeypadModifier ] else True
        if curpos==0 and len(text)>0:
            if text[curpos]=="-":
                self.setCursorPosition(curpos+1)
        if key==Qt.Key_Period:
            if curpos<(len(text)-self.DECIMAL_POINT_POS):
                self.setCursorPosition(len(text)-self.DECIMAL_POINT_POS)
            else:
                self.setCursorPosition(len(text)-self.DECIMAL_POINT_POS-1)
            return
        if key==Qt.Key_Minus:
            if len(text)>0:
                if text[0]=="-":
                    self.setText(text[1:])
                    curpos-=1
                else:
                    self.setText("-"+text)
                    curpos+=1
            else:
                self.setText("-"+text)
                curpos+=1
            self.setCursorPosition(curpos)
            return
        if event.modifiers() == Qt.NoModifier :
            if key in [Qt.Key_Backspace,Qt.Key_Delete] and (self.hasSelectedText()==False):
                cur_pos_left = len(text)-self.cursorPosition()
                if key==Qt.Key_Backspace:
                    if len(text)==0:
                        return
                    if cur_pos_left<=self.DECIMAL_POINT_POS-1:
                        text=text[:curpos-1]+text[curpos:]
                        self.setText(text+"0")
                        self.setCursorPosition(curpos-1)
                        return
                    elif (cur_pos_left<=self.DECIMAL_POINT_POS and self.DECIMAL_POINT_POS>0) or \
                        text[curpos-1]==',':
                        self.setCursorPosition(curpos-1)
                elif key == Qt.Key_Delete:
                    if cur_pos_left<=self.DECIMAL_POINT_POS+1 and cur_pos_left<>0 and self.DECIMAL_POINT_POS>0:
                        if cur_pos_left==self.DECIMAL_POINT_POS+1: curpos+=1
                        text=text[:curpos]+text[curpos+1:]
                        self.setText(text+"0")
                        self.setCursorPosition(curpos)
                        return
        QLineEdit.keyPressEvent(self,event)
        if "." in selected_text and not was_modifiers:
            self.setCursorPosition(len(QLineEdit.text(self))-self.DECIMAL_POINT_POS-1)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    MyApp = QApplication(sys.argv)
    w=zzLineEdit("-1123456.1234", "999,99,99,999.9999")
    w.setFont(QFont("Arial Bold", 54))
    w.show()
    sys.exit(app.exec_())

       #уберем не цифры
        newnum=""
        for i in txt:
            if str(i) in "-0123456789.":newnum+=i