One Line Solution 
IntuitionHere we're concatenating two pandas DataFrames vertically. The intuition is to use pandas' built-in concat functionApproachBy default, pd.concat([df1,d
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->
Here we're concatenating two pandas DataFrames vertically. The intuition is to use pandas' built-in concat function

# Approach
<!-- Describe your approach to solving the problem. -->
By default, ```pd.concat([df1,df2])``` function stacks the DataFrames vertically (row-wise)

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->
**O(n + m)**
n =  number of rows in df1
m =  number of rows in df2 
Because each row from both DataFrames needs to be copied into the new DataFrame :)

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->
**O(n + m)**

# Code
```pythondata []
import pandas as pd

def concatenateTables(df1: pd.DataFrame, df2: pd.DataFrame) -> pd.DataFrame:
    return pd.concat([df1,df2])
```
['Python', 'Pandas']