first interaction in python environment setuplaunch python interpreter to get prompt "we will start learning python programming by writing "helloprogram depending on the needswe can program either at python command prompt or jupyter (command lineor we can write python script file in spyder or jupyter or pycharm in all the optionspython issues prompt whereit expects input commands type print("hello"in different software and observe the results after executing the command in python interpreterwrite the statement at the command prompt and press enter to view the result in spyder and jupyter softwareclick on "runto view the results in pycharmclick on run menu and choose on "runoptionselect the appropriate file name to execute the program and for viewing the results command line versus scripts command line is generally used for single line and script is used for multiple commands if we want to execute only one functionhighlight the function and click on run current selection butif we want to use the whole file containing many functions to get executed togetherwe need to write script for the same and click on run comments comments are like text notes for user' help in python program and they are ignored by the compiler single line comment start with example #this is my first program multi-line comments can be created using ""(three double quotes in start and end of comment blockidentifiers python identifier is name used to identify variablefunctionor any other user-defined item python is case-sensitive programming language thusamount and amount are two different identifiers in python the name of identifier must follow the naming rules the name of an identifier can be composed of lettersdigitsand the underscore character an identifier starts with letter to za to zor an underscore '_followed by zero or more lettersunderscoresand digits ( to python does not allow punctuation characters such as @$and within identifiers examplebillamountanswera sd etc it should be noted here that unlike any other programming languagethere is no need to declare the variable in python an identifier is generally associated with an expression or value the operator means assignmentnot mathematical equality the statement copies the value stored in variable into variable it should be noted that the numeric value is written without double quotes and string value is enclosed in double quotes " string contains characters that are similar to character literalsplain charactersescape sequencesand universal characters examplefor the statementrevenue revenue is an identifier which has the value in pythonwe say that revenue is assigned value and the assignment operator (=is used for the statement city="punestores the string value of pune in the city identifier