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Python practice problems help beginners to become experts in a python programming language with a small amount of practice effort.
Write a pandas program to print a selected row.
name age 2 John 27
iloc by position or loc by label.import pandas as pddf = pd.DataFrame({"name": ["Alex", "John", "Peter"], "age": [30, 27, 29]}, index=[1, 2, 3])print(df.loc[[2]])name age 2 John 27
Double brackets keep the result as a DataFrame.
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Write a pandas program to print selected columns.
name and age from a table with Sr.no, name, age
name age 0 Alex 30 1 John 27 2 Peter 29
df[["name", "age"]].import pandas as pddf = pd.DataFrame({"sr_no": [1, 2, 3], "name": ["Alex", "John", "Peter"], "age": [30, 27, 29]})print(df[["name", "age"]])name age 0 Alex 30 1 John 27 2 Peter 29
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Write a pandas program to print the last n rows.
n square 8 9 81 9 10 100
tail(n).import pandas as pddf = pd.DataFrame({"n": range(1, 11), "square": [i * i for i in range(1, 11)]})print(df.tail(2))n square 8 9 81 9 10 100
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Write a pandas program to print the first n rows.
n square 0 1 1 1 2 4 2 3 9
head(n).import pandas as pddf = pd.DataFrame({"n": range(1, 11), "square": [i * i for i in range(1, 11)]})print(df.head(3))n square 0 1 1 1 2 4 2 3 9
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Write a pandas program to convert a dictionary into a DataFrame.
name age 0 Alex 30 1 John 27 2 Peter 29
import pandas as pddf = pd.DataFrame({"name": ["Alex", "John", "Peter"], "age": [30, 27, 29]})print(df)name age 0 Alex 30 1 John 27 2 Peter 29
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Write a pandas program to find the index of the smallest and largest values.
[54, 25, 38, 87]
1 3
idxmin() and idxmax().import pandas as pds = pd.Series([54, 25, 38, 87])print(s.idxmin(), s.idxmax())1 3
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Write a pandas program to convert date strings in different formats into datetimes.
["2 Feb 2020", "5/11/2021", "7-8-2022"]
0 2020-02-02 1 2021-11-05 2 2022-08-07 dtype: datetime64[us]
pd.to_datetime(..., format="mixed", dayfirst=True).import pandas as pds = pd.Series(["2 Feb 2020", "5/11/2021", "7-8-2022"])print(pd.to_datetime(s, format="mixed", dayfirst=True))0 2020-02-02 1 2021-11-05 2 2022-08-07 dtype: datetime64[us]
format="mixed" parses each value separately; dayfirst=True reads 5/11/2021 as 5 November.
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Write a pandas program to count the characters of each word.
["Virat", "Rohit", "Pant", "Shikhar"]
0 5 1 5 2 4 3 7 dtype: int64
str.len().import pandas as pdprint(pd.Series(["Virat", "Rohit", "Pant", "Shikhar"]).str.len())0 5 1 5 2 4 3 7 dtype: int64
“Virat” and “Rohit” have 5 letters; the original sample showed 6.
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Write a pandas program to make the first and last letter of each word uppercase.
["sqatools", "python", "data", "science"]
0 SqatoolS 1 PythoN 2 DatA 3 SciencE dtype: str
map a small function.import pandas as pds = pd.Series(["sqatools", "python", "data", "science"])print(s.map(lambda w: w[0].upper() + w[1:-1] + w[-1].upper()))0 SqatoolS 1 PythoN 2 DatA 3 SciencE dtype: str
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Write a pandas program to extract items at positions 1, 4 and 7.
[3, 0, 3, 2, 2, 0, 3, 3, 2]
1 0 4 2 7 3 dtype: int64
iloc with a list.import pandas as pds = pd.Series([3, 0, 3, 2, 2, 0, 3, 3, 2])print(s.iloc[[1, 4, 7]])1 0 4 2 7 3 dtype: int64
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