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- length(column_expression)
- DESCRIPTION:
Function returns the number of characters in the expression.
PARAMETERS:
column_expression:
Required Argument.
Specifies a ColumnExpression of a string column or a string literal.
If the argument is null, then result is null.
Format of a ColumnExpression of a string column: '<dataframe>.<dataframe_column>.expression'.
Supported column types: CHAR, VARCHAR, or CLOB
NOTE:
Function accepts positional arguments only.
EXAMPLES:
# Load the data to run the example.
>>> load_example_data("dataframe", "admissions_train")
>>>
# Create a DataFrame on 'admissions_train' table.
>>> admissions_train = DataFrame("admissions_train")
>>> admissions_train
masters gpa stats programming admitted
id
22 yes 3.46 Novice Beginner 0
36 no 3.00 Advanced Novice 0
15 yes 4.00 Advanced Advanced 1
38 yes 2.65 Advanced Beginner 1
5 no 3.44 Novice Novice 0
17 no 3.83 Advanced Advanced 1
34 yes 3.85 Advanced Beginner 0
13 no 4.00 Advanced Novice 1
26 yes 3.57 Advanced Advanced 1
19 yes 1.98 Advanced Advanced 0
>>>
# Example returns length of character string in "programming" column.
# Import func from sqlalchemy to execute length function.
>>> from sqlalchemy import func
# Create a sqlalchemy Function object.
>>> length_func_ = func.length(admissions_train.programming.expression)
>>>
# Pass the Function object as input to DataFrame.assign().
>>> df = admissions_train.assign(length_programming_=length_func_)
>>> print(df)
masters gpa stats programming admitted length_programming_
id
5 no 3.44 Novice Novice 0 6
34 yes 3.85 Advanced Beginner 0 8
13 no 4.00 Advanced Novice 1 6
40 yes 3.95 Novice Beginner 0 8
22 yes 3.46 Novice Beginner 0 8
19 yes 1.98 Advanced Advanced 0 8
36 no 3.00 Advanced Novice 0 6
15 yes 4.00 Advanced Advanced 1 8
7 yes 2.33 Novice Novice 1 6
17 no 3.83 Advanced Advanced 1 8
>>>
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