PYTHON

range function with for loop in python

# Syntax - range(start, stop, step) - you must use integers, floats cannot be used

for i in range(3):
    print(i)
# output - automatically taken start = 0 and step = 1, we have given stop = 3 (excluding 3)

for i in range(0, 4):
    print(i)
# output - We have given start = 0 and stop = 4 (excluding 4), automatically taken step =1

for i in range(0, 5, 2):
    print(i)
# output - We have given start = 0, stop = 5 (excluding 5), step = 2

for i in range(0, -4, -1):
    print(i)
# output - We can go even backwards and also to negative numbers

[_ for _ in range(n)]

"""Use of _ as a variable
It is to indicate throwaway variables, 
...i.e. variables that are not reused anywhere else (as they are...
        ...not logically important) but for syntax reasons you have to put

This saves space for variables that are actually reused...
...and provides a good mental model for essential and unessential parts...
...of your code

Of course, take this as a guideline. 
There are instances where naming those variables are better for readability...
...especially in group projects

Check out the source for more info!
"""

lst1 = [_ for _ in range(10)]
print(lst1)
# [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

for _ in range

When you are not interested in some values returned by a function we use underscore in place of variable name . 
Basically it means you are not interested in how many times the loop is run till now just that it should run some specific number of times overall.

python for loop range

#Python range() example
print("Numbers from range 0 to 6")
for i in range(6):
    print(i, end=', ')

python for in range

# i start from 0 going to 4 "5 steps"
for i in range(5):
	print(i)

# output
0
1
2
3
4

for range python

for x in range(0, 10):
    print(x)
#this  is used similarly as the for(var i =0; i<x.length)... in some other languages*/

for _ in range() in python

## ignoring a value
a, _, b = (1, 2, 3) # a = 1, b = 3
print(a, b)

## ignoring multiple values
## *(variable) used to assign multiple value to a variable as list while unpacking
## it's called "Extended Unpacking", only available in Python 3.x
a, *_, b = (7, 6, 5, 4, 3, 2, 1)
print(a, b)

for _ in range python

When you are not interested in some values returned by a function 
we use underscore in place of variable name . 
Basically we don't care about the iterator value, just that it 
should run some specific number of times.

python range for loop

for i in range(n):
	print(i)

for i in range python

for elt in Liste:
  print(elt)

for range python

for variable in range (69): # Runs the code below 69 times, sets the var "variable" to the index
  print(variable) # Prints the var "variable" (every time the number will be bigger)
 print("Done") # This will not get sent 69 times.