change specific cell in pandas dataframe code example

Example 1: change dataframe value by index

x    y
A  NaN  NaN
B  NaN  NaN
C  NaN  NaN

df.at['C', 'x'] = 10

Example 2: How to colour a specific cell in pandas dataframe

import pandas as pd
import numpy as np
np.random.seed(24)
df = pd.DataFrame({'A': np.linspace(1, 10, 10)})
df = pd.concat([df, pd.DataFrame(np.random.randn(10, 4), columns=list('BCDE'))],
               axis=1)
df.iloc[0, 2] = np.nan
df.iloc[3, 3] = np.nan
df.iloc[4, 1] = np.nan
df.iloc[9, 4] = np.nan
print("Original array:")
print(df)
print("\nBackground:black - fontcolor:yelow")
df.style.set_properties(**{'background-color': 'black',
                           'color': 'yellow'})

Example 3: How to colour a specific cell in pandas dataframe

def color_negative_red(val):
    """
    Takes a scalar and returns a string with
    the css property `'color: red'` for negative
    strings, black otherwise.
    """
    color = 'red' if val < 0 else 'black'
    return 'color: %s' % color