Python in a nutshell (2 Part Series)
Lets start with the Hello World of Python.
>>> print("Hello, World") Hello, World >>>
We know one rule, a computer program does only what we have specified it to do. So how did the print function printed a new line character?
Lets investigate the print function with one of our bestfriends called the help function.
>>> help(print) print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False) Prints the values to a stream, or to sys.stdout by default. Optional keyword arguments: file: a file-like object (stream); defaults to the current sys.stdout. sep: string inserted between values, default a space. end: string appended after the last value, default a newline. flush: whether to forcibly flush the stream.
(Type q to exit the help)
So from this we can understand that after printing the value, it entered a new line character. Lets see different arguments in action:
>>> print("Hello, World", end='') Hello, World>>> print(1, 2, 3) 1 2 3 >>> print(1, 2, 3, sep='-') 1-2-3 >>>
Okay next thing now is to take input from the user, which can be done as:
>>> a = input("Enter your name:") Enter your name: Anurag >>> print(a) Anurag >>>
The input function returns a string. Don't worry about different data types, we will cover them later.
You can find the type of an object using type function:
>>> type(a) <class 'str'>
So the object returned by the input function is of class str.
Lets try our new bestfriend help function on it:
>>> help(input) Help on built-in function input in module builtins: input(prompt=None, /) Read a string from standard input. The trailing newline is stripped. The prompt string, if given, is printed to standard output without a trailing newline before reading input. If the user hits EOF (*nix: Ctrl-D, Windows: Ctrl-Z+Return), raise EOFError. On *nix systems, readline is used if available.
It is important to remember what type of object a function returns.
- Make help function your best friend.
- Use type function to find the type of an object.
- Know what to provide to a function and more importantly what it returns.
In Part-2, we will discuss about the importing different modules and different data structures in Python.
Python 2 Python 3 is used.
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