Replace value in dataframe column in python not working

Question

I have this pandas dataframe:

     Score  # Bads  # Goods
(470, 480]       3        2
(480, 490]       5        6
(490, 500]      20       24
(500, 510]      63       99
(510, 520]     176      230
(520, 530]     555      825
(530, 540]    1272     2105
(540, 550]    3298     7084
(550, 560]    7559    18819
(560, 570]   11293    31546
(570, 580]    7475    24476
(580, 590]    7982    31377
(590, 600]    4699    22787
(600, 610]    3125    18899
(610, 620]    1741    11193
(620, 630]     771     6553
(630, 640]     346     3603
(640, 650]     144     1756
(650, 660]      56      778
(660, 670]      23      277
(670, 680]       5       84
(680, 690]       0       18
(690, 700]       0        2

I need to replace the commas (",") in the Score column with the symbol " -< ". I have coded this:

df['Score'] = df['Score'].replace(',', "-<")
print(df)

but the commas are not replaced at all: they remain in the dataframe.

     Score  # Bads  # Goods
(470, 480]       3        2
(480, 490]       5        6
(490, 500]      20       24
(500, 510]      63       99
(510, 520]     176      230
(520, 530]     555      825
(530, 540]    1272     2105
(540, 550]    3298     7084
(550, 560]    7559    18819
(560, 570]   11293    31546
(570, 580]    7475    24476
(580, 590]    7982    31377
(590, 600]    4699    22787
(600, 610]    3125    18899
(610, 620]    1741    11193
(620, 630]     771     6553
(630, 640]     346     3603
(640, 650]     144     1756
(650, 660]      56      778
(660, 670]      23      277
(670, 680]       5       84
(680, 690]       0       18
(690, 700]       0        2

I don't understand why the code above doesn't work.

Answer 1

You missed a .str part:

df['Score'] = df['Score'].str.replace(',', "-<")