diff --git a/python_lesson_1.py b/python_lesson_1.py new file mode 100644 index 0000000..c4466d1 --- /dev/null +++ b/python_lesson_1.py @@ -0,0 +1,364 @@ +print("hello world") + +"""to check python version +import sys +print(sys.version) +""" +#variables +x = 5 +y = "hello sai!" +print(y , x) + +#casting for speecifying data type +x = int(4) +y = str("sai") +z = float(4) +s = x + z +print (s) + +#type() function +print(type(s)) + +#multiple value assign to multiple variables +x , y , z = "orange" , "apple", "papaya" +print(x,y,z) + +#one value to multiple variables +x = y = z = "alphanso mango" +print(x) +print(y) +print(z) + +#unpack a collection +fruits = ["raspberry" , "gauva" , "mango"] +x, y, z = fruits +print(x) +print(y) +print(z) + +# + operator adds for int and concatenate for string +print( 20 + 12) +print("sai" + "deshmane") + +#global variable +x = "awesome" +def myfunction(): + print("python is" + x); + +myfunction + +#local & global having same name , variable unside func called as local +x = "awesome" +def myfunc(): + x = "fantastic" + print("python is" + x) + +myfunc() +print("python is" + x) + +#but we declare variable as global inside a function +def myfunct(): + global x + x = "damnnnnnn" +myfunct() +print("python is " + x) + +#we can also change global variable (here awesome is overwrite by fantasticcc) +x = "awesome" +def myfun(): + global x + x = "fantasticcccc" +myfun() +print("python is" + x) + +#boolean type +sai = True +print(sai) +print(type(sai)) + +#list +x = ["sai" , "vishu" , "vishwa"] +print (x) +print(x[2]) + +#tuple(immutable) +x = ("sai" , "vishu", "vishwa") +print(x) +print(x[0]) + +#range +y = 8 +x = range(y) +print(x) +print(type(x)) + +#dictionary +x = {"name" : "john" , "age" : 36} +print(x) +print(type(x)) + +#set +x = {"apple" , "banana" , "cherry"} +print(x) +print(type(x)) + +#frozenset + +x = frozenset({"apple" , "banana", "watermelon"}) +print(x) +print(type(x)) + +x = 1 #int +x = 1.0 #float +x = 1j #complex + +#e indicates power of 10, number contaoning is float +x = 10e1 +print(x) + +#complex with j as imaginary part +x = 3+5j +print(x) +print(type(x)) + + +#type conversion +x = 1 # int +y = 2.8 # float +z = 1j # complex + +#convert from int to float: +a = float(x) + +#convert from float to int: +b = int(y) + +#convert from int to complex: +c = complex(x) + +print(a) +print(b) +print(c) + +print(type(a)) +print(type(b)) +print(type(c)) + +#random module +import random +print(random.randrange(1, 100)) + +#multiline string +a = """hey im sai and i jst 143<3 mauuu """ +print(a) +print(len(a)) + +#check if certain character or phrase is in string or not using keyword 'in' +txt = ["sai" , "vishu", "vishwa"] +if "sai" in txt: + print(True) + +#To check if a certain phrase or character is NOT present in a string, +# we can use the keyword not in +txt = ["sai" , "vishu", "vishwa"] +if "vishwajeet" not in txt: + print(False) + +#slicing char at 11 not included means printed from index 6 to 10 only +b = "hello world" +print(b[6:11]) +print(b[:6]) #print from start idx i.e 0 to 5 +print(b[2:]) #print from idx 2 to end + +#-11 -10-9 -8 -7 -6 -5 -4 -3 -2 -1 +# h e l l o w o r l d ! +# 0 1 2 3 4 5 6 7 8 9 10 11 + +b = "hello world!" +print(b[-5:-2]) + +#upper() +a = "sai" +print(a.upper()) + +#lower() +a = "sai" +print(a.lower()) + +# strip() method removes any whitespace from the beginning or the end +a = " sai " +print(a.strip()) + +#replace() method replaces a string with another string +a = "sai" +print(a.replace("sai" ,"vishu")) + +#split() method splits the string into substrings if it finds instances of the separato +a = "Hello, World!" +print(a.split(",")) + +# we can combine strings and numbers by using f-strings or the format() method! +age = 21 +txt = f"my age is {age}" +print(txt) + +#A placeholder can contain variables, operations, functions, and +# modifiers to format the value. +#Add a placeholder for the price variable +price = 59 +txt = f"the price is {price}" +print(txt) + +#Display the price with 2 decimals, colon : followed by a legal formatting type, like .2f +price = 59 +txt = f"the price is {price :.2f}" +print(txt) + +# placeholder can contain Python code, like math operations +txt = f"the price is {20 * 20}" +print(txt) + +# to insert characters the are illegeal in a string,use an escape character +#1. \" +txt = "sai is a \"viking\" " +print(txt) + +# 2.\' +# txt = 'sai is a \'viking\' ' +print(txt) + +#3.\\ (enters one backslash) +txt = "this will insert one\\ backslash" +print(txt) + +#4.\n (for new line) +txt = "sai is \n viking" +print(txt) + +#5.\r (Carriage Return) +txt = "Hello\rworld!" +print(txt) + +#6.\t (Tab) +txt = "hello \t world" +print(txt) + +#7.\b (Backspace) +txt = "hello \b world" +print(txt) + +#8.\f (Form Feed) +txt = "hello \f world" +print(txt) + +#A backslash followed by an 'x' and a hex number represents a hex value: +txt = "\x48\x65\x6c\x6c\x6f" +print(txt) + +#string methods + +#count() Returns the number of times a specified value occurs in a string +txt = "hello world!" +print(txt.count('l')) + +#ccasefold() Converts string into lower case +txt = "HELLO world!" +print(txt.casefold()) + +#endswith() Returns true if the string ends with the specified value +txt = "hello world!" +print(txt.endswith('!')) + +#find() Searches the string for a specified value and returns the position of where it was found +txt = "hello world!" +print(txt.find('o')) + +#index() Searches the string for a specified value and returns the position of where it was found +txt = "hello world!" +print(txt.index('o')) + +#isdecimal() Returns True if all characters in the string are decimals +txt = "hello world!" +print(txt.isdecimal()) + +#more methods based on string check on w23 school + +#boolean +print(10 > 9) +print(10 < 9) +print(10 == 9) + +#bool() function allows you to evaluate any value, and give you True or False in return, +print(bool("hello")) +print(bool(15)) + +#evalute the two variables +x = "hello" +y = 15 +print(bool("hello")) +print(bool(15)) + +#Almost any value is evaluated to True if it has some sort of content. +#Any string is True, except empty strings. +#Any number is True, except 0. +#Any list, tuple, set, and dictionary are True, except empty ones. + +#The following will return True: +print(bool("abc")) +print(bool(123)) +print(bool(["apple", "cherry", "banana"])) + +#The following will return False: +print(bool(False)) +print(bool(None)) +print(bool(0)) +print(bool("")) +print(bool(())) +print(bool([])) +print(bool({})) + +#One more value, or object in this case, evaluates to False, and that is if you have +# an object that is made from a class with a __len__ function that returns 0 or False +class myclass(): + def __len__(self): + return 0 +myobj = myclass() +print(bool(myobj)) + +#Print the answer of a function: +def myFunction() : + return True +print(myFunction()) + +#Print "YES!" if the function returns True, otherwise print "NO!": +def myFunction() : + return True +if myFunction(): + print("YES!") +else: + print("NO!") + +#Check if an object is an integer or not: +x = 200 +print(isinstance(x, int)) + +a = "hello world" +print(a[1]) + +for x in "hello world": + print (x) + +a = "hello world" +print(len(a)) + +#Print only if "free" is present +txt = "sai" +list = txt +if 'a' in txt: + print(txt.index('a')) + +#Check if "expensive" is NOT present in the following text +txt = "i am sai" +print("sai" not in txt) +if "vishwa" not in txt: + print("vishwa in not present") \ No newline at end of file