Why must ‘self’ be used explicitly in method definitions and calls?

Sequence Types — str, unicode, list, tuple, bytearray, buffer, xrange

functools — Higher-order functions and operations on callable objects

argparse — Parser for command-line options, arguments and sub-commands

aepack — Conversion between Python variables and AppleEvent data containers

sysconfig — Provide access to Python’s configuration information

hacknetnodes[i].moneyGainRatePerSecond() (hacknetnodes[i] method)

hacknetnodes[i].getLevelUpgradeCost(n);() (hacknetnodes[i] method)