df.columns = df.columns.to_flat_index()

df[col].str.replace("src-text", "tgt", regex=True)

df[col].str.replace("http\S+", "", regex=True)

df.drop(columns=["col-name0", "col-name1"], inplace=True)

df = df.assign(col_test=[x*2 for x in range(1000)])

df["col_test"] = [x*2 for x in range(1000)]

from tqdm import tqdm
tqdm.pandas()
df.progress_apply(func)

df = pd.DataFrame({"a": [1,2,3,1,4,3,3]})
df["a"].value_counts().to_frame()
   a
3  3
1  2
2  1
4  1

for index in df.index:
    print(index, df.at[index, "a"])

df.drop_duplicates(subset=["column_name"], inplace=True)

pd.merge(a, b, on=["key"], how="left").merge(c, on=["key"], how="left")

pd.merge(a, b, suffixes=("", "_right"), on=["key"], how="left")

pd.merge(a, b, left_on="left_key", right_on="right_key", how="left")

df.reset_index(drop=True, inplace=True)

codes, uniques = pd.factorize(["a", "b", "a", "c", None])
display(codes) # array([ 0,  1,  0,  2, -1])

df.foobar = df.foobar + 1

agg_df = df.groupby(["foo", "bar", ...]) \
            .agg(
               mean=(target, "mean"), 
               median=(target, "median"), 
               skew=(target, "skew"),
               kurtosis=(target, pd.DataFrame.kurt),
               std=(target, "std"))

index = df[df["First Tooltip"] <= 100].index

df.loc[index, "Period"] = df.loc[index, "Period"] * 3

df.apply(something_function, axis=1)

import pandas as pd

df.sort_values(by=["tweet_date"], inplace=True)
dropwhiles = []
flg = False
for score in sub["score"]:
    if score >= 1.0:
        flg = True
    dropwhiles.append(flg)
df.drop(dropwhiles, axis=0, inplace=True) # Falseのindexをdropする

s1 = pd.Series([1,2,3,4,5])
s2 = pd.Series([2,3,4])
set(s1).symmetric_difference(s2) # {1, 5}が得られる