1. Variable: is a letter or symbol, the value of the program is running to produce a record, the next step is calculated for use. The equivalent of X
2. For example:
a = 3 + 5 # equal sign means that the assignment, the assignment to the variable value of the right-hand side to the left.
3. Single-line comments: #
Multi-line comments: '' 'multiline' ''
4. The variable string:
#a=18
print (a) # variable a print (a) = 18
print ( "a") # a letter string of a print ( "a") = a