Answers for "r dataframe change column value based on condition"

change pandas column value based on condition

In [41]:
df.loc[df['First Season'] > 1990, 'First Season'] = 1
df

Out[41]:
                 Team  First Season  Total Games
0      Dallas Cowboys          1960          894
1       Chicago Bears          1920         1357
2   Green Bay Packers          1921         1339
3      Miami Dolphins          1966          792
4    Baltimore Ravens             1          326
5  San Franciso 49ers          1950         1003

r change column based on condition

# If a condition is met in a specific column (column "b" is 0), 
# change the value in column "est". Here the value is replaced
# by the value for "a" in that same row where b == 0.

df$est[df$b == 0] <- df$a[df$b == 0]