How to add a column to DataFrame with constant value?

Let us understand with the help of an example:

# Importing Pandas package as pd
import pandas as pd

# Creating a dictionary
d = {
    'A':[1,2,3,4],
    'B':[1,2,3,4]
}

# Creating DataFrame
df = pd.DataFrame(d)

# Display original DataFrame
print("Original DataFrame:\n",df,"\n")

# Creating a new column with similar/ constant value
df['C'] = pd.Series(['Hello, This is a new column' for i in range(len(df.index))])

# Display modified DataFrame
print("Modified DataFrame\n",df)

Output: