42, 93, 135 Test

addition = True
reverse = False

data = ''
name = 'Pi'

choice = raw_input('Enter constant Choice (Pi, 2Pi, Phi, e, em, A, cat, kl, rt): ')

if choice.lower().strip() == '2pi':
    name = '2Pi'
    with open('/path/to/2pi_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'phi':
    name = 'Phi'
    with open('/path/to/phi_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'e':
    name = 'e'
    with open('/path/to/e_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'em':
    name = 'Euler-Mascheroni'
    with open('/path/to/em_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'a':
    name = 'A'
    with open('/path/to/A.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'cat':
    name = 'Catalan'
    with open('/path/to/catalan_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'kl':
    name = 'Khinchin-Levy'
    with open('/path/to/khinchin-levy_20m.txt') as the_file: data = the_file.read()
elif choice.lower().strip() == 'rt':
    name = 'Sqrt2'
    with open('/path/to/sqrt_2.txt') as the_file: data = the_file.read()
else:
    name = 'Pi'
    with open('/path/to/pi_20m.txt') as the_file: data = the_file.read()

data = data[:100000]

target = 1

while True:
    num_input = raw_input('Enter number to search for: ').strip()
    if num_input.isdigit():
        if int(num_input) > 0:
            target = int(num_input)
            break

target_len = len(str(target)) + 1

answer = raw_input('\nPress Enter to do addition. Enter anything to do subtraction.')

if answer != '':
    addition = False
    target_len = 10

matches = []

print('')

for i in range(0, len(data)):
    for length in range(1, target_len):     # Iterate through every section length up to target length
        section = data[i:i + length]                        # n length chunk of Pi
        end_of = i + length

        add_up = section
        add_up2 = end_of

        if reverse:
            add_up = section[::-1]
            add_up2 = int(str(end_of)[::-1])

        if addition == True:
            if int(add_up) + add_up2 == target:
                if [int(section), end_of] not in matches:
                    matches.append([int(section), end_of])

                    s_stripped = str(int(section))

                    instance = ''
                    first_occur = len(data.split(s_stripped, 1)[0] + s_stripped)

                    if first_occur == end_of: instance = ' first'

                    print(s_stripped + instance + ' appears in ' + name + ' at the end of ' + str(end_of) + ' digits (' + str(int(add_up)) + ' + ' + str(add_up2) + ' = ' + str(target) + ')')
        else:
            if abs(int(add_up) - add_up2) == target:

                a_msg = int(add_up)
                b_msg = int(add_up2)

                if a_msg < b_msg:
                    a_msg = int(add_up2)
                    b_msg = int(add_up)

                if [int(section), end_of] not in matches:
                    matches.append([int(section), end_of])

                    s_stripped = str(int(section))

                    instance = ''
                    first_occur = len(data.split(s_stripped, 1)[0] + s_stripped)

                    if first_occur == end_of: instance = ' first'

                    print(s_stripped + instance + ' appears in ' + name + ' at the end of ' + str(end_of) + ' digits (' + str(a_msg) + ' - ' + str(b_msg) + ' = ' + str(target) + ')')