# For Loop with Two Variables (for i j in python)

## for i j in python

The Python expression `for i, j in XXX` allows you to iterate over an iterable `XXX` of pairs of values. For example, to iterate over a list of tuples, this expression captures both tuple values in the loop variables `i` and `j` at once in each iteration.

Here’s an example:

```for i, j in [('Alice', 18), ('Bob', 22)]:
print(i, 'is', j, 'years old')```

Output:

```Alice is 18 years old
Bob is 22 years old```

Notice how the first loop iteration captures `i='Alice'` and `j=18`, whereas the second loop iteration captures `i='Bob'` and `j=22`.

## for i j in enumerate python

The Python expression `for i, j in enumerate(iterable)` allows you to loop over an iterable using variable `i` as a counter (0, 1, 2, …) and variable `j` to capture the iterable elements.

Here’s an example where we assign the counter values `i=0,1,2` to the three elements in `lst`:

```lst = ['Alice', 'Bob', 'Carl']
for i, j in enumerate(lst):
print(i, j)
```

Output:

```0 Alice
1 Bob
2 Carl```

Notice how the loop iteration capture:

• `i=0` and `j='Alice'`,
• `i=1` and `j='Bob'`, and
• `i=2` and `j='Carl'`.

🌍 Learn More: The `enumerate()` function in Python.

## for i j in zip python

The Python expression `for i, j in zip(iter_1, iter_2)` allows you to align the values of two iterables `iter_1` and `iter_2` in an ordered manner and iterate over the pairs of elements. We capture the two elements at the same positions in variables `i` and `j`.

Here’s an example that zips together the two lists `[1,2,3]` and `[9,8,7,6,5]`.

```for i, j in zip([1,2,3], [9,8,7,6,5]):
print(i, j)
```

Output:

```1 9
2 8
3 7```

🌍 Learn More: The `zip()` function in Python.

## for i j in list python

The Python expression `for i, j in list` allows you to iterate over a given list of pairs of elements (list of tuples or list of lists). In each iteration, this expression captures both pairs of elements at once in the loop variables `i` and `j`.

Here’s an example:

```for i, j in [(1,9), (2,8), (3,7)]:
print(i, j)```

Output:

```1 9
2 8
3 7```

## for i j k python

The Python expression `for i, j, k in iterable` allows you to iterate over a given list of triplets of elements (list of tuples or list of lists). In each iteration, this expression captures all three elements at once in the loop variables `i` and `j`.

Here’s an example:

```for i, j, k in [(1,2,3), (4,5,6), (7,8,9)]:
print(i, j, k)```

Output:

```1 2 3
4 5 6
7 8 9```

## for i j in a b python

Given two lists `a` and `b`, you can iterate over both lists at once by using the expression `for i,j in zip(a,b)`.

Given one list `['a', 'b']`, you can use the expression `for i,j in enumerate(['a', 'b'])` to iterate over the pairs of (identifier, list element) tuples.

## Summary

The Python `for` loop is a powerful method to iterate over multiple iterables at once, usually with the help of the `zip()` or `enumerate()` functions.

``````for i, j in zip(range(10), range(10)):
# (0,0), (1,1), ..., (9,9)``````

If a list element is an iterable by itself, you can capture all iterable elements using a comma-separated list when defining the loop variables.

``````for i,j,k in [(1,2,3), (4,5,6)]:
# Do Something``````