Write a python program to read input a string and replace all occurrences of the first character of the string with '_'. Testcase: "restart" Expected output: _esta_t

Help? Using python, write a program that lets the user enter a string and displays the character that appears most frequently in the string.    Should i start with string lower?

String:  abcdefghijklmnopqrstuvwxyzyxwvutsr   qponmlkjihgfedcba   Make a program that: reads a letter from standard input print the above string up to this letter For example, if the letter was c, the output would be: abcba   Must use a function and Python

This following program is intended to print something sensible. .ORIG x3800 LEA R1, ? A ADD R1, R1, N-2 LDR Re, R1, Ne BRZ F D OUT E BR A HALT G FILL H .STRINGZ "Pehrveeht Isnip irtegnomputs" I .FILL -END The question mark should be replaced with a label. The program may, even with any replacement, contain an error. This program contains an error. O Yes, it contains an error. O No, it does not contain an error. If it does contain an error, enter the label of the line which is at fault, but if it does not contain an error enter a single period. What is the (exact) sensible message which the program intends to print out?