
Python pandas DataFrame - Convert Python list to pandas DataFrame
pandas is a Python library analyzing data. DataFrame
is a basic data form in pandas.
import pandas
a = [29, 19, 40, 21]
df = pandas.DataFrame(a)
print(df)
# 0
# 0 29
# 1 19
# 2 40
# 3 21
DataFrame
is a table with data, index, column name. The indexes start from 0 like Python list and in the above case the column name is 0
.
Add columns
Setting columns
argument, the header of dataframe has columns.
import pandas
a = [29, 19, 40, 21]
df = pandas.DataFrame(a, columns=['Population'])
print(df)
# Population
# 0 29
# 1 19
# 2 40
# 3 21
List of tuples
import pandas
a = [
('Texas', 29),
('New York', 19),
('California', 40),
('Florida', 21),
]
df = pandas.DataFrame(a, columns=['State', 'Population'])
print(df)
# State Population
# 0 Texas 29
# 1 New York 19
# 2 California 40
# 3 Florida 21
If a
is the list of State-Population tuples, pandas DataFrame
shows the above table. Check columns
argument is a list and the number of each tuple of a
and columns
are the same.
The first element of tuple corresponds to State, the second corresponds to Population.
Get all the rows by columns
import pandas
a = [
('Texas', 29),
('New York', 19),
('California', 40),
('Florida', 21),
]
df = pandas.DataFrame(a, columns=['State', 'Population'])
print(df)
# State Population
# 0 Texas 29
# 1 New York 19
# 2 California 40
# 3 Florida 21
states = df[['State']]
print(states)
# State
# 0 Texas
# 1 New York
# 2 California
# 3 Florida
df[['State']]
represents all the State
rows.
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