# File: strfind.py
# Find a substring in a string
#
# Matt Bishop, MHI 289I, Fall 2021
#
while True:
    # read in a string; quit on EOF
    try:
        instr = input("Enter a string to be searched: ")
    except EOFError:
        break
    except:
        print("Unknown error; EOF to end")
        continue
    #
    # put quotes around the string to show its boundaries when it is printed
    #
    prstr = '"' + instr + '"'
    # read in the string you want to find; quit on EOF
    try:
        findstr = input("Enter the (sub)string you want to find: ")
    except EOFError:
        break
    except:
        print("Unknown error; EOF to end")
        continue
    #
    # put quotes around the string to show its boundaries when it is printed
    #
    prfindstr = '"' + findstr + '"'
    #
    # find the substring
    #
    # first, -1 on failure
    indx = instr.find(findstr)
    if (indx == -1):
        print(prfindstr, "does not occur in", prstr)
    else:
        print(prfindstr, "first occurs at position", indx, "in", prstr)
    indx = instr.rfind(findstr)
    if (indx == -1):
        print(prfindstr, "does not occur in", prstr)
    else:
        print(prfindstr, "last occurs at position", indx, "in", prstr)

    # next, exceptions if it doesn't occur
    try:
        indx = instr.index(findstr)
    except ValueError as msg:
        print(prfindstr, "does not occur in", prstr, "--", msg)
    else:
        print(prfindstr, "first occurs at position", indx, "in", prstr)
    try:
        indx = instr.rindex(findstr)
    except ValueError as msg:
        print(prfindstr, "does not occur in", prstr, "--", msg)
    else:
        print(prfindstr, "last occurs at position", indx, "in", prstr)