If Else statements
In Python the if else statements look like below.
number = 3 if number == 0: print('zero') elif number % 2 == 0: print('event') else: print('odd')
Note here it is
elif and not
else if, also instead of curly braces we have colon as the denotion of start of block. In Python indentation is very important if program is to compile and work, for this the statements under if and other constructs are indented properly. Also there is no need for parantheses for stating if conditions.
There is no
? : operator in Python, instead it has following construct.
number = 3 odd_or_even = 'odd' if number % 2 != 0 else 'even' print(odd_or_even)
The construct is basically
expression1 if condition else expression2
Unlike Java, Python does not have a for loop construct where we can initialize a counter
i and loop until
i breaks some condition. In Python, for loop is used to iterate over the elements of a sequence(such as string, list). It’s syntax is as belows :
for i in range(1, 5): print(i)
This will print numbers from 1 to 4. Below is for loop with break statement.
for i in range(1, 5): print(i) if i == 3: break
This will print numbers from 1 to 3. In Python
else block can be used with looping constructs, idea is that whenever the looping condition becomes false the else block is executed unless the loop was not exited using break. Below is an example:
for i in range(1, 5): print(i) else: print('outside range')
This will print numbers from 1 to 4 and then
outside range will be printed. Now note the below code, there is a break statement. In this case numbers from 1 to 3 will be printed and that else block will not be executed.
for i in range(1, 5): print(i) if i == 3: break else: print('outside range')
While loops has similar construct as for loops, only difference being that instead of iterating over sequence, it executes until the condition is being met. Let’s have a look:
num = 10 while num > 0: print(num) num = num - 1 if num == 2: break else: print('num not greater than 0 anymore')
else statement will not be executed since
break will come into play.
The looping constructs can also have
continue statements and they work same as Java.
There are no switch statements in Python !