The French elections have handed President Valery Giscard d'Estaing what one of the Paris papers calls a "second spring." He has been proved right in his basic strategy, and he has built a major party in the Parliament.

Still, he has at best an opportunity. For France remains a country divided, and the president has nipping at his heels the dynamic Gaullist leader Jacques Chirac.

The president's special quality in French politics is a unique awareness of the second industrial revolution that has transformed his country in the postwar era. High growth rates through the 1960s converted France into a modern economy with a high technology sector and big exports. Expansion of housing and social services ensures that even in difficult times nobody goes without basic necessities.

To be sure there is gross inequalityof wealth - perhaps more so than in any advanced country.

But Giscard had developed a program to meet more difficulties. As presented in his recentt book, "French Democracy," he wants a higher minimum wage, more progressive taxes, decentralization of government and a freeing up of a price-control system that tends to push banks and other enterprises in favor of the haves against the have-nots.

For the first three years of his presidency, from 1974 forward, Giscard's reform ideas were blocked by two political barriers. On the left, the Communists and Socialists under Francois Mitterrand denounced them as mere palliatives designed to maintain the status quo.

On the right, there was a Gaullist majority under former Prime Minister Chirac. He opposed reform as concessions to the left wing. Where the president played for time to let the Socialists and Communists fall apart, Chirac resigned as prime minister because Giscard would not take on the left wing in an early election.

The voting on the last two Sundays justified the president's instinct for moderate reform in almost every way. Though the election came at a bad time - with inflation running over 10 percent and unemployment over a million - candidates indentified with Giscard scored a marked triumph.

The Union for French Democracy, a party organized in the president's behalf in the last days of the campaign, won 137 seats and emerged as the second largest party in the Assembly. Individuals personally supported by Giscard - notably Prime Minister Raymond Barre - won handily what had been considered hotly contested seats.

As the president predicted, moreover, the Socialists and Communists fell apart. The Communists first inflicted upon the Socialists a "common program," which called for something like a thousand different nationalizations. That show of strength scared French voters, and as a result the United Left, instead of winning the 53 percentt majority predicted for the first ballot on March 12, won only 49.5 percent.

The two parties next patched up a hasty alliance that would have given the Communists a good shot at ministerial offices. That scared the voters more, and lowered the left-wing percentage in the run-off last Sunday. By election night there was open bickering among the leaders, with Mitterrand himself blaming the Communists for the defeat of the left.

As to the Gaullists, they fell from 170 to 148 seats in the Parliament. Many of the old guard who had opposed the Giscard reforms were beaten. The drop probably would have been much greater except for the dynamic campaigning of Chirac - which probably explains the record 85 percent turnout in the run-off election on Sunday.

Theoretically, the president has the makings of a good moderate majority. The Socialists are in disarray, and he can pull some of them over to his moderate reform program. The Gaullists, having suffered because of their identity with the past, also look ripe for presidential cajolery.

But the Socialists and the Communists still command nearly half the French electorate. If the Socialists desert the left for a center coalition, they will be abandoning some part of their following to the detested Communists. Moreover, the Gaullists remain the largest party in the assembly, and Chirac has ambitions to take on Giscard in the race for the presidency in 1981.

So Giscard remains far from having total command. He has averted a leftwing takeover and probably any serious social unrest. But he has not changed the system. French politics still lags behind French social, economic and international realities, and the "second spring" requires more than just waiting a couple of weeks.