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NameError indicates that a variable has been used that is undefined. In this case, the error message is saying that the variable ‘pd’ has been used but it has not been defined before. To fix this, you need to define the variable ‘pd’ before it is used by assigning it a value or data type.
One common error you may encounter when using Python is:
NameError: name 'pd' is not defined
This error usually occurs when you import the python library , but fail to give it the alias of pd when importing it.
The following examples illustrate how this error occurs in practice and how you can quickly fix it.
Example 1: Use import pandas as pd
Suppose you import the pandas library using the following code:
import pandas
If you then attempt to create a pandas DataFrame, you’ll get the following error:
#create pandas DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
'assists': [5, 7, 7, 9, 12, 9, 9, 4],
'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
#attempt to print DataFrame
print(df)
Traceback (most recent call last):
1 import pandas
----> 2 df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
3 'assists': [5, 7, 7, 9, 12, 9, 9, 4],
4 'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
5
NameError: name 'pd' is not defined
To fix this error, you need provide the alias of pd when importing pandas
import pandas as pd
#create pandas DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
'assists': [5, 7, 7, 9, 12, 9, 9, 4],
'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
#print DataFrame
print(df)
points assists rebounds
0 25 5 11
1 12 7 8
2 15 7 10
3 14 9 6
4 19 12 6
5 23 9 5
6 25 9 9
7 29 4 12
Example 2: Use import pandas
Suppose you import the pandas library using the following code:
import pandas
If you then attempt to create a pandas DataFrame, you’ll get the following error:
#create pandas DataFrame
df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
'assists': [5, 7, 7, 9, 12, 9, 9, 4],
'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
#attempt to print DataFrame
print(df)
Traceback (most recent call last):
1 import pandas
----> 2 df = pd.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
3 'assists': [5, 7, 7, 9, 12, 9, 9, 4],
4 'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
5
NameError: name 'pd' is not defined
To fix this error, you could simply choose not to use the alias of pd at all:
import pandas
#create pandas DataFrame
df = pandas.DataFrame({'points': [25, 12, 15, 14, 19, 23, 25, 29],
'assists': [5, 7, 7, 9, 12, 9, 9, 4],
'rebounds': [11, 8, 10, 6, 6, 5, 9, 12]})
#print DataFrame
print(df)
points assists rebounds
0 25 5 11
1 12 7 8
2 15 7 10
3 14 9 6
4 19 12 6
5 23 9 5
6 25 9 9
7 29 4 12
Note: The syntax “import pandas as pd” is commonly used because it offers a more concise way to use pandas functions. Instead of typing “pandas” each time, you can simply type in “pd” which is quicker and easier to read.