I am having some trouble with the DataFrame and while loop:

A     B
5     10
5     10
10    5

I am trying to have a while loop that:

while (Column A < Column B):Column A = Column A + (Column B / 2)Column B = Column B / 2

Any ideas how to do this.

You can vectorise this calculation to avoid explicit loops:

mask = df['A'] < df['B']df.loc[mask, 'A'] = df['A'] + df['B'] / 2
df.loc[mask, 'B'] = df['B'] / 2print(df)#       A    B
# 0  10.0  5.0
# 1  10.0  5.0
# 2  10.0  5.0