Display number with leading zeros

Question

How do I display a leading zero for all numbers with less than two digits? ``` 1 → 01 10 → 10 100 → 100 ```

Accepted Answer

In Python 2 (and Python 3) you can do:

```
number = 1
print("%02d" % (number,))
```

Basically % is like `printf` or `sprintf` (see docs).

For Python 3.+, the same behavior can also be achieved with `format`:

```
number = 1
print("{:02d}".format(number))
```

For Python 3.6+ the same behavior can be achieved with f-strings:

```
number = 1
print(f"{number:02d}")
```

Solution